Posts Tagged ‘howto’

Check server Internet connectivity Speedtest from Linux terminal CLI

Friday, August 7th, 2020

check-server-console-speedtest

If you are a system administrator of a dedicated server and you have no access to Xserver Graphical GNOME / KDE etc. environment and you wonder how you can track the bandwidth connectivity speed of remote system to the internet and you happen to have a modern Linux distribution, here is few ways to do a speedtest.
 

1. Use speedtest-cli command line tool to test connectivity


speedtest-cli is a tiny tool written in python, to use it hence you need to have python installed on the server.
It is available both for Redhat Linux distros and Debians / Ubuntus etc. in the list of standard installable packages.

a) Install speedtest-cli on Fedora / CentOS / RHEL
 

On CentOS / RHEL / Scientific Linux lower than ver 8:

$ sudo yum install python

On CentOS 8 / RHEL 8 user type the following command to install Python 3 or 2:

$sudo yum install python3
$ sudo yum install python2


On Fedora Linux version 22+

$ sudo dnf install python
$ sudo dnf install pytho3


Once python is at place download speedtest.py or in case if link is not reachable download mirrored version of speedtest.py on pc-freak.net here
 

$ wget -O speedtest-cli https://raw.githubusercontent.com/sivel/speedtest-cli/master/speedtest.py
$ chmod +x speedtest-cli


Then it is time to run script speedtest-screenshot-linux-terminal-console-cli-cmd
To test enabled Bandwidth on the server

$ python speedtest-cli


b) Install speedtest-cli on Debian

On Latest Debian 10 Buster speedtest is available out of the box in regular .deb repositories, so fetch it with apt
 

# apt install –yes speedtest-cli


You can give now speedtest-cli a try with –bytes arguments to get speed values in bytes instead of bits or if you want to generate an image with test results in picture just like it will appear if you use speedtest.net inside a gui browser, use the –share option

speedtest-screenshot-linux-terminal-console-cli-cmd-options

2. Getting connectivity results of all defined speedtest test City Locations


Speedtest has a list of servers through which a Upload and Download speed is tested, to run speedtest-cli to test with each and every server and get a better picture on what kind of connectivity to expect from your server towards the closest region capital cities, fetch speedtest-servers.php list and use a small shell loop below is how:

root@pcfreak:~#  wget http://www.speedtest.net/speedtest-servers.php
–2020-08-07 16:31:34–  http://www.speedtest.net/speedtest-servers.php
Преобразувам www.speedtest.net (www.speedtest.net)… 151.101.2.219, 151.101.66.219, 151.101.130.219, …
Connecting to www.speedtest.net (www.speedtest.net)|151.101.2.219|:80… успешно свързване.
HTTP изпратено искане, чакам отговор… 301 Moved Permanently
Адрес: https://www.speedtest.net/speedtest-servers.php [следва]
–2020-08-07 16:31:34–  https://www.speedtest.net/speedtest-servers.php
Connecting to www.speedtest.net (www.speedtest.net)|151.101.2.219|:443… успешно свързване.
HTTP изпратено искане, чакам отговор… 307 Temporary Redirect
Адрес: https://c.speedtest.net/speedtest-servers-static.php [следва]
–2020-08-07 16:31:35–  https://c.speedtest.net/speedtest-servers-static.php
Преобразувам c.speedtest.net (c.speedtest.net)… 151.101.242.219
Connecting to c.speedtest.net (c.speedtest.net)|151.101.242.219|:443… успешно свързване.
HTTP изпратено искане, чакам отговор… 200 OK
Дължина: 211695 (207K) [text/xml]
Saving to: ‘speedtest-servers.php’
speedtest-servers.php                  100%[==========================================================================>] 206,73K  –.-KB/s    in 0,1s
2020-08-07 16:31:35 (1,75 MB/s) – ‘speedtest-servers.php’ saved [211695/211695]

Once file is there with below loop we extract all file defined servers id="" 's 
 

root@pcfreak:~# for i in $(cat speedtest-servers.php | egrep -Eo 'id="[0-9]{4}"' |sed -e 's#id="##' -e 's#"##g'); do speedtest-cli  –server $i; done
Retrieving speedtest.net configuration…
Testing from Vivacom (83.228.93.76)…
Retrieving speedtest.net server list…
Retrieving information for the selected server…
Hosted by Telecoms Ltd. (Varna) [38.88 km]: 25.947 ms
Testing download speed……………………………………………………………………..
Download: 57.71 Mbit/s
Testing upload speed…………………………………………………………………………………………
Upload: 93.85 Mbit/s
Retrieving speedtest.net configuration…
Testing from Vivacom (83.228.93.76)…
Retrieving speedtest.net server list…
Retrieving information for the selected server…
Hosted by GMB Computers (Constanta) [94.03 km]: 80.247 ms
Testing download speed……………………………………………………………………..
Download: 35.86 Mbit/s
Testing upload speed…………………………………………………………………………………………
Upload: 80.15 Mbit/s
Retrieving speedtest.net configuration…
Testing from Vivacom (83.228.93.76)…

…..


etc.

For better readability you might want to add the ouput to a file or even put it to run periodically on a cron if you have some suspcion that your server Internet dedicated lines dies out to some general locations sometimes.
 

3. Testing UPlink speed with Download some big file from source location


In the past a classical way to test the bandwidth connectivity of your Internet Service Provider was to fetch some big file, Linux guys should remember it was almost a standard to roll a download of Linux kernel source .tar file with some test browser as elinks / lynx / w3c.
speedtest-screenshot-kernel-org-shot1 speedtest-screenshot-kernel-org-shot2
or if those are not at hand test connectivity on remote free shell servers whatever file downloader as wget or curl was used.
Analogical method is still possible, for example to use wget to get an idea about bandwidtch connectivity, let it roll below 500 mb from speedtest.wdc01.softlayer.com to /dev/null few times:

$ wget –output-document=/dev/null http://speedtest.wdc01.softlayer.com/downloads/test500.zip

$ wget –output-document=/dev/null http://speedtest.wdc01.softlayer.com/downloads/test500.zip

$ wget –output-document=/dev/null http://speedtest.wdc01.softlayer.com/downloads/test500.zip

# wget -O /dev/null –progress=dot:mega http://cachefly.cachefly.net/10mb.test ; date
–2020-08-07 13:56:49–  http://cachefly.cachefly.net/10mb.test
Resolving cachefly.cachefly.net (cachefly.cachefly.net)… 205.234.175.175
Connecting to cachefly.cachefly.net (cachefly.cachefly.net)|205.234.175.175|:80… connected.
HTTP request sent, awaiting response… 200 OK
Length: 10485760 (10M) [application/octet-stream]
Saving to: ‘/dev/null’

     0K …….. …….. …….. …….. …….. …….. 30%  142M 0s
  3072K …….. …….. …….. …….. …….. …….. 60%  179M 0s
  6144K …….. …….. …….. …….. …….. …….. 90%  204M 0s
  9216K …….. ……..                                    100%  197M=0.06s

2020-08-07 13:56:50 (173 MB/s) – ‘/dev/null’ saved [10485760/10485760]

Fri 07 Aug 2020 01:56:50 PM UTC


To be sure you have a real picture on remote machine Internet speed it is always a good idea to run download of random big files on a certain locations that are well known to have a very stable Internet bandwidth to the Internet backbone routers.

4. Using Simple shell script to test Internet speed


Fetch and use speedtest.sh


wget https://raw.github.com/blackdotsh/curl-speedtest/master/speedtest.sh && chmod u+x speedtest.sh && bash speedtest.sh

5. Using iperf to test connectivity between two servers 

iperf is another good tool worthy to mention that can be used to test the speed between client and server.

To use iperf install it with apt and do on the server machine to which bandwidth will be tested:

# iperf -s 

On the client machine do:

# iperf -c 192.168.1.1 

where 192.168.1.1 is the IP of the server where iperf was spawned to listen.

6. Using Netflix fast to determine Internet connection speed on host


Fast

fast is a service provided by Netflix. Its web interface is located at Fast.com and it has a command-line interface available through npm (npm is a package manager for nodejs) so if you don't have it you will have to install it first with:

# apt install –yes npm

Note that if you run on Debian this will install you some 249 new nodejs packages which you might not want to have on the system, so this is useful only for machines that has already use of nodejs.

$ fast

     82 Mbps ↓


The command returns your Internet download speed. To get your upload speed, use the -u flag:

$ fast -u

   ⠧ 80 Mbps ↓ / 8.2 Mbps ↑

7. Use speedometer / iftop to measure incoming and outgoing traffic on interface


If you're measuring connectivity on a live production server system, then you might consider that the measurement output might not be exactly correct especially if you're measuring the Uplink / Downlink on a Heavy loaded webserver / Mail Server / Samba or DNS server.
If this is the case a very useful tools to consider to extract the already taken traffic used on your Incoming and Outgoing ( TX / RX ) Network interfaces
are speedometer and iftop, they're present and installable depending on the OS via yum / apt or the respective package manager.


To install on Debian server:

# apt install –yes iftop speedometer


The most basic use to check the live received traffic in a nice Ncurses like text graphic is with: 

# speedometer -r 


speedometer-check-received-transmitted-network-traffic-on-linux1

To generate real time ASCII art graph on RX / TX traffic do:

# speedometer -r eth0 -t eth0


speedometer-check-received-transmitted-network-traffic-on-linux

# iftop -P -i eth0


iftop-show-statistics-on-connections-screenshot-pcfreak

Send TCP / UDP strings and commands to Local and Remote Applications without netcat with Bash

Friday, July 24th, 2020

bash-open-network-tcp-udp-connections-from-shell-gnu-bash-shell-shell-logo

Did you ever needed to send TCP / UDP packets manually to send commands to local or remote applications, having a fully functional BASH Shell but not having the luxury to have NC (Netcat Swiss Army Knife of Networking) tool?
This happens if you have some Linux based embeded device as Arduino or a Linux server with a high security PCI requirement which can't affort to have Netcat in place or another portable hardware with a Linux kernel, that needs to communicate in UDP for any reason but you don't want to waste additional 28KB or physically you have access to a Linux device that doesn't have netcat but you want to be able to send UDP externally …

SInce some time in newer GNU Bash's releases support for TCP / UDP data sending is described in Bash's Manual and should be working it is not as good as you might expect but for a small things it could save you the day.

The syntax to use it is:
 

 /dev/protocol/IP/PORT


To open new socket connection to a UDP / TCP protocol with bash you have to simply open a new Shell handler (lets say 3) to:

/dev/tcp/your-url.com/80


or

/dev/udp/83.228.93.76/53

1. Get GOOGLE HTML Source with simple BASH / Getting URL Index with bash sockets


If you happen to have access to a machine where no network downloader tool or a text browser such as curl, wget, lynx, links is available but you want to dump the content of a index.html or any other URL with simply bash you can do it like so:
 

exec 3<>/dev/tcp/www.google.com/80
echo -e "GET / HTTP/1.1\r\n\r\n" >&3 

cat <&3

If you need to open a connection to a Internet Domain with bash and store the output into a separate .html file:

exec 3<>/dev/tcp/www.google.com/80
echo -e "GET / HTTP/1.1\r\n\r\n" >&3 

cat <&3 | tee -a output.html


Note that this will work only if you're logged into into an interactive shell.
If you want instead do it from a shell script (and omit usage) of wget etc. use something like bash_sockets_google_connect.sh basic script :

#!/bin/bash
exec 3<>/dev/tcp/www.google.com/80
printf "GET /\r\n\r\n" >&3
while IFS= read -r -u3 -t2 line || [[ -n “$line” ]]; do echo "$line"; done
exec 3>&-
exec 3<&-

2. Sending UDP protocol data via bash socket


To send test  variables or commands data to localhost (127.0.0.1) UDP listening service:
 

echo 'TEST COMMAND' > /dev/udp/127.0.0.1/538

echo "Any UDP data" > /dev/udp/127.0.0.1/3000


If you happent to have netcat or running on a bash shell that doesn't properly support TCP / UDP sending you can always do it netcat way:

echo "Command" | nc -u -w0 127.0.0.1 3000


Of course this little hack is useful just for simple things and eventually for more comlex stuff and scripting you would like to use a fully functional HTML reader ( W3C compliant Web Browser )
still  for a quick dirty stuff Bash socketing from the console rocks pretty much ! 🙂

Get daily E-Mail Reports statistics on postfix Linux mail server

Tuesday, July 14th, 2020

https://pc-freak.net/images/Postfix-email-server-logo.svg-1

I've had today a task at work to monitor a postfix mail send and received emails (MAIL FROM / RPCT TO) and get out a simple statistics on what kind of emails are coming and going out from the Postfix SMTP on a server?

Below is shortly explained how I did it plus you will learn how you can use something more advanced to get server mail count, delivery status, errors etc. daily.
 

1. Using a simple script to process /var/log/messages

For that I made a small script to do the trick, the script simply checks mail delivery logged information from /var/log/maillog process a bit sort and logs in a separate log daily.

#!/bin/sh
# Process /var/log/maillog extract from= and to= mails sort
# And log mails to $LOGF
# Author Georgi Georgiev 14.07.2020

DATE_FORM=$(date +'%m_%d_%y_%H_%M_%S_%h_%m');
LOG='/home/gge/mail_from_to-mails';
LOGF="$LOG.$DATE_FORM.log";
CUR_DATE=$(date +'%m_%d_%y_%T');
echo "Processing /var/log/maillog";
echo "Processing /var/log/maillog" > $LOGF;
echo >>$LOGF
echo "!!! $CUR_DATE # Sent MAIL FROM: addresses: !!!" >> $LOGF;
grep -E 'from=' /var/log/maillog|sed -e 's#=# #g'|awk '{ print $8 }'|sed -e 's#<# #g' -e 's#># #g' -e 's#\,##'|sort -rn|uniq >> $LOGF;

echo "!!! $CUR_DATE # Receive RCPT TO: addresses !!!" >>$LOGF;
grep -E 'to=' /var/log/maillog|sed -e 's#=# #g'|awk '{ print $8 }'|sed -e 's#<# #g' -e 's#># #g' -e 's#\,##'|sort -rn|uniq >> $LOGF;


You can get a copy of the mail_from_to_collect_mails_postfix.sh script here.

I've set the script to run via a crond scheduled job once early in the mornthing and I'll leave it like that for 5 days or so to get a good idea on what are the mailboxes that are receiving incoming mail.

The cron I've set to use is as follows:

# crontab -u root -l 
05 03 * * *     sh /home/gge/mail_from_to.sh >/dev/null 2>&1

This will be necessery later for a Email Server planned migration to relay its mail via another MTA host.

2. Getting More Robust Postifx Mail Statistics from logs


My little script is of course far from best solution to get postfix mail statistics from logs.

If you want something more professional and you need to have a daily report on what mails sent to mail server and mails sent from the MTA to give you information about the Email delivery queue status, number of successful and failed emails from a mail sender / recipient and a whole bunch of useful info you can use something more advanced such as pflogsumm perl script to get daily / weekly monthly mail delivery statistics.

What can pflogsumm do for you ?

Pflogsumm is a log analyzer/summarizer for the Postfix MTA. It is
designed to provide an overview of Postfix activity, with just enough
detail to give the administrator a “heads up” for potential trouble
spots and fixing any SMTP and email related issues.

Pflogsumm generates summaries and, in some cases, detailed reports of
mail server traffic volumes rejected and bounced email and server
warnings, errors, and panics.

At the time of writting this article it is living on jimsun.linxnet.com just in case if pflogsumm.pl's official download location disappears at some time in future here is pflogsumm-1.1.3.tar.gz mirror stored on pc-freak.net

– Install pflogsumm

Use of pflogsumm is pretty straight forward, you download unarchive the script to some location such as /usr/local/bin/pflogsumm.pl  add the script executable flag and you run it to create a Postfix Mail Log statistics report for you

wget http://jimsun.linxnet.com/downloads/pflogsumm-1.1.3.tar.gz -O /usr/local/src/pflogsumm-1.1.3.tar.gz

# mkdir -p /usr/local/src/
# cd /usr/local/src/
# tar -zxvf pflogsumm-1.1.3.tar.gz
# cd pflogsumm-1.1.3/

# mv /usr/local/pflogsumm-1.1.3/pflogsumm.pl /usr/local/bin/pflogsumm
# chmod a+x /usr/local/bin/pflogsumm


That's all, assuming you have perl installed on the system with some standard modules, we're now good to go: 

To give it a test report to the command line:

# /usr/local/bin/pflogsumm -d today /var/log/maillog

pflogsumm-log-summary-screenshot-linux-received-forwarded-bounced-rejected

To generate mail server use report and launch to some email of choice do:

# /usr/local/bin/pflogsumm -d today /var/log/maillog | mail -s Mailstats your-mail@your-domain.com


To make pflogsumm report everyday various interesting stuff such as (message deferrals, message bounce, details, smtp delivery failures, fatal errors, recipients by message size etc. add some cronjob like below to the server:

# /usr/sbin/pflogsumm -d yesterday /var/log/maillog | mail -s Mailstats | mail -s Mailstats your-mail@your-domain.com

If you need a GUI graphical mail monitoring in a Web Browser, you will need to install a webserver with a perl / cgi support,  RRDTools and MailGraph.

linux-monitoring-mail-server-with-mailgraph.cgi

How to install KVM Kernel-based Virtual Machine Virtualization on Linux

Sunday, October 14th, 2018

install-KVM-Kernel-based-Virtual-Machine-virtualization-on-Linux

If you want to run multiple virtual machines on GNU / Linux server or your Linux powered Desktop you have the possibility to use a couple of Virtual Machines just to name a few VirtualBox and VMWare are the option the native way to do it is using the Linux kernel via a loadable kernel module called KVM (Kernel-based Virtual Machine).
Though Oracle's Virtualbox generally works and you could add new test beds virtual machines (install multiple Linux / *BSD OS) it is not fully Free Software and not even fully open source licensed, VMWare even though superior as a Virtualization product is proprietary and its application costs a lot of money which not each develpoper or small / mid-sized company could afford.

Once the kvm.ko module is loaded your Linux kernel turns into a full-featured Virtual Machine Hypervisor.
Starting with Linux kernel 2.6.X the KVM Hypervisor is available and easy to install virtually all modern Linux distributions Redhat / CentOS Debian / Ubuntu etc. support it and its up to running few commands to install and start using the Power of Kernel embedded Virtualization.

KVM could be used to run in parallel multiple Operating Systems such as Windows / Linux / FreeBSD and others of BSDs family,  each running under a separate virtual machine with its private dedicated (isolated), disc, graphic card, network card etc.

To start up I assume you have already installed some kind of Linux distribution either locally or on a remote dedicated server.
 

1. Installing KVM on Debian GNU / Linux / Ubuntu / Mint and other deb based distros

Using APT tool install below packages:

root@jeremiah:~# apt install –yes qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils libguestfs-tools genisoimage virtinst libosinfo-bin

2. Installing virt-manager GUI to manage Virtual servers

root@jeremiah:~# apt-cache show virt-manager|grep -i desc -A 1
Description-en: desktop application for managing virtual machines
 It presents a summary view of running domains and their live performance &

Description-md5: 9f7f584744b77cdacc2291f2a8ac220e
Homepage: http://virt-manager.et.redhat.com/

root@jeremiah:~# apt install –yes virt-manager


virtual-manager-kvm-gnu-linux-virtual-machines-cpu-hdd-load-statistics-screenshot

virtual-manager-fedora-28-linux-virtual-machine-settings-screenshot


3. Configure bridged networking to allow access to newly configured VMs

Bridging has to be added via /etc/network/interfaces therefore it is a good idea to create a backup of it before modifying:

# cp -rpf /etc/network/interfaces /etc/network/interfaces.bakup-$(echo $(date '+%Y-%m-%d-%H'))

# vim /etc/network/interfaces

auto br0
 iface br0 inet static
         address 10.15.44.26
         netmask 255.255.255.192
         broadcast 10.15.44.63
         dns-nameservers 10.0.80.11 10.0.80.12
         # set static route for LAN
      post-up route add -net 10.0.0.0 netmask 255.0.0.0 gw 10.18.44.1
      post-up route add -net 161.26.0.0 netmask 255.255.0.0 gw 10.18.44.1
         bridge_ports eth0
         bridge_stp off
         bridge_fd 0
         bridge_maxwait 0
 
 # br1 setup with static wan IPv4 with ISP router as a default gateway
 auto br1
 iface br1 inet static
         address 192.168.222.51
         netmask 255.255.255.248
         broadcast 192.168.222.55
         gateway 192.168.222.49
         bridge_ports eth1
         bridge_stp off
         bridge_fd 0
         bridge_maxwait 0

Once file is saved in vim editor restart the networking.

# systemctl restart network.manager

To verify whether the bridge has been succesfully upped.

root@jeremiah:/home/hipo/kvm# brctl show
bridge name    bridge id        STP enabled    interfaces
virbr0        8000.525400cb1cd1    yes        virbr0-nic

4. List all installable Virtual OS images
 

root@jeremiah:/home/hipo/kvm# virt-builder -list
centos-6                 x86_64     CentOS 6.6
centos-7.0               x86_64     CentOS 7.0
centos-7.1               x86_64     CentOS 7.1
centos-7.2               aarch64    CentOS 7.2 (aarch64)
centos-7.2               x86_64     CentOS 7.2
centos-7.3               x86_64     CentOS 7.3
centos-7.4               x86_64     CentOS 7.4
centos-7.5               x86_64     CentOS 7.5
cirros-0.3.1             x86_64     CirrOS 0.3.1
cirros-0.3.5             x86_64     CirrOS 0.3.5
debian-6                 x86_64     Debian 6 (Squeeze)
debian-7                 sparc64    Debian 7 (Wheezy) (sparc64)
debian-7                 x86_64     Debian 7 (wheezy)
debian-8                 x86_64     Debian 8 (jessie)
debian-9                 x86_64     Debian 9 (stretch)
fedora-18                x86_64     Fedora® 18
fedora-19                x86_64     Fedora® 19
fedora-20                x86_64     Fedora® 20
fedora-21                aarch64    Fedora® 21 Server (aarch64)
fedora-21                armv7l     Fedora® 21 Server (armv7l)
fedora-21                ppc64      Fedora® 21 Server (ppc64)
fedora-21                ppc64le    Fedora® 21 Server (ppc64le)
fedora-21                x86_64     Fedora® 21 Server
fedora-22                aarch64    Fedora® 22 Server (aarch64)
fedora-22                armv7l     Fedora® 22 Server (armv7l)
fedora-22                i686       Fedora® 22 Server (i686)
fedora-22                x86_64     Fedora® 22 Server
fedora-23                aarch64    Fedora® 23 Server (aarch64)
fedora-23                armv7l     Fedora® 23 Server (armv7l)
fedora-23                i686       Fedora® 23 Server (i686)
fedora-23                ppc64      Fedora® 23 Server (ppc64)
fedora-23                ppc64le    Fedora® 23 Server (ppc64le)
fedora-23                x86_64     Fedora® 23 Server
fedora-24                aarch64    Fedora® 24 Server (aarch64)
fedora-24                armv7l     Fedora® 24 Server (armv7l)
fedora-24                i686       Fedora® 24 Server (i686)
fedora-24                x86_64     Fedora® 24 Server
fedora-25                aarch64    Fedora® 25 Server (aarch64)
fedora-25                armv7l     Fedora® 25 Server (armv7l)
fedora-25                i686       Fedora® 25 Server (i686)
fedora-25                ppc64      Fedora® 25 Server (ppc64)
fedora-25                ppc64le    Fedora® 25 Server (ppc64le)
fedora-25                x86_64     Fedora® 25 Server
fedora-26                aarch64    Fedora® 26 Server (aarch64)
fedora-26                armv7l     Fedora® 26 Server (armv7l)
fedora-26                i686       Fedora® 26 Server (i686)
fedora-26                ppc64      Fedora® 26 Server (ppc64)
fedora-26                ppc64le    Fedora® 26 Server (ppc64le)
fedora-26                x86_64     Fedora® 26 Server
fedora-27                aarch64    Fedora® 27 Server (aarch64)
fedora-27                armv7l     Fedora® 27 Server (armv7l)
fedora-27                i686       Fedora® 27 Server (i686)
fedora-27                ppc64      Fedora® 27 Server (ppc64)
fedora-27                ppc64le    Fedora® 27 Server (ppc64le)
fedora-27                x86_64     Fedora® 27 Server
fedora-28                i686       Fedora® 28 Server (i686)
fedora-28                x86_64     Fedora® 28 Server
freebsd-11.1             x86_64     FreeBSD 11.1
scientificlinux-6        x86_64     Scientific Linux 6.5
ubuntu-10.04             x86_64     Ubuntu 10.04 (Lucid)
ubuntu-12.04             x86_64     Ubuntu 12.04 (Precise)
ubuntu-14.04             x86_64     Ubuntu 14.04 (Trusty)
ubuntu-16.04             x86_64     Ubuntu 16.04 (Xenial)
ubuntu-18.04             x86_64     Ubuntu 18.04 (bionic)
opensuse-13.1            x86_64     openSUSE 13.1
opensuse-13.2            x86_64     openSUSE 13.2
opensuse-42.1            x86_64     openSUSE Leap 42.1
opensuse-tumbleweed      x86_64     openSUSE Tumbleweed


5. Create Virtual Machine OS-es from scratch with virt-builder

Below we'll create two images one for Fedora 28 and 1 for Debian 9 using the virt-builder (a tool to build virtual images quickly), the images that could be used are shown through below virt-builder –list command.
 

# iso='fedora-28';
# iso1='debian-9';

# sudo virt-builder $iso \
     –size=10G \
     –format qcow2 -o /var/lib/libvirt/images/$iso-vm1.qcow2 \
     –hostname $iso-vm1 \
     –network \
     –timezone Europe/Sofia

[   3.3] Downloading: http://libguestfs.org/download/builder/fedora-28.xz
[   5.2] Planning how to build this image
[   5.2] Uncompressing
[  20.8] Resizing (using virt-resize) to expand the disk to 10.0G
[  50.8] Opening the new disk
[  53.7] Setting a random seed
[  53.7] Setting the hostname: fedora-28-vm1
[  53.7] Setting the timezone: Europe/Sofia
[  53.7] Setting passwords
virt-builder: Setting random password of root to YMTkxaJIkEU24Ytf

[  54.7] Finishing off
                   Output file: /var/lib/libvirt/images/fedora-28-vm1.qcow2
                   Output size: 10.0G
                 Output format: qcow2
            Total usable space: 9.3G
                    Free space: 8.2G (87%)

# sudo virt-builder $iso1 \
     –size=10G \
     –format qcow2 -o /var/lib/libvirt/images/$iso-vm1.qcow2 \
     –hostname $iso1-vm1 \
     –network \
     –timezone Europe/Sofia

[   3.2] Downloading: http://libguestfs.org/download/builder/debian-9.xz
[   4.1] Planning how to build this image
[   4.1] Uncompressing
[  16.9] Resizing (using virt-resize) to expand the disk to 10.0G
[  40.1] Opening the new disk
[  42.9] Setting a random seed
virt-builder: warning: random seed could not be set for this type of guest
[  42.9] Setting the hostname: debian-9-vm1
[  43.6] Setting the timezone: Europe/Sofia
[  43.6] Setting passwords
virt-builder: Setting random password of root to JtzEYGff9KxL5jCR
[  44.3] Finishing off
                   Output file: /var/lib/libvirt/images/debian-9-vm1.qcow2
                   Output size: 10.0G
                 Output format: qcow2
            Total usable space: 9.8G
                    Free space: 9.0G (91%)


vim bridged.xml

<network>
  <name>br0</name>
  <forward mode="bridge"/>
  <bridge name="br0"/>
</network>

# sudo virsh net-define –file bridged.xml
# sudo virsh net-autostart br0
# sudo virsh net-start br0

Above two commands will download pre-packaged KVM isos and store them inside /var/lib/libvirt/images/ you see also the root (administrator) password for both ISOs printed out.

root@jeremiah:/home/hipo/kvm# ls -ld /var/lib/libvirt/images/*
-rw-r–r– 1 root         root         10739318784 Oct 12 23:45 /var/lib/libvirt/images/debian-9-vm1.qcow2
-rw-r–r– 1 root         root         10739318784 Oct 12 23:46 /var/lib/libvirt/images/fedora-28-vm1.qcow2

To access directly the new created VMs as we have specified the –vnc option it is possible to directly vnc to the new host with VNC client (in linux I use vncviewer), on Windows you can use something like TightVNC.
 

6. Use official Linux distributions ISO boot files to install into KVM VM


Those who would like to run inside KVM VM Linux could do it directly using installable ISO files and install the set of Linux with the required packages, just like installing a fresh new Linux on a bare-metal machine.
To do so download your ISO image from the net (either from official distro website or a mirror website, in case if you need to spin an older version) and use virt-install to run the installer inside KVM.

root@jeremiah:~# cd /var/lib/libvirt/boot/;
root@jeremiah:~# wget http://mirrors.netix.net/centos/7.5.1804/isos/x86_64/CentOS-7-x86_64-DVD-1804.iso

# sudo virt-install \
–virt-type=kvm \
–name centos7 \
–ram 2048 \
–vcpus=2 \
–os-variant=centos7.0 \
–virt-type=kvm \
–hvm \
–cdrom=/var/lib/libvirt/boot/CentOS-7-x86_64-DVD-1804.iso \
–network=bridge=br0,model=virtio \
–network=bridge=br1,model=virtio \
–graphics vnc \
–disk path=/var/lib/libvirt/images/centos7.qcow2,size=40,bus=virtio,format=qcow2


7. List newly created VMs with Virsh command

root@jeremiah:/home/hipo/kvm# virsh list –all
 Id    Name                           State
—————————————————-
 3     fedora-28                      running
 –     debian9                        shut off

The –all parameter lists all available VMs ready to spin, if you want to check what are the VMs that are only running use instead:

root@jeremiah:/home/hipo/kvm# virsh list
 Id    Name                           State
—————————————————-
 3     fedora-28                      running

8. Install Virtual Machine OS-es

Below lines will install 2 Virtual machines one Fedora 28 and Debian 9

 os='fedora-28';
virt-install –import –name $os \
    –ram 2048 \
    –vcpu 2 \
    –disk path=/var/lib/libvirt/images/$os-vm1.qcow2,format=qcow2 \
    –os-variant fedora-unknown \
    –network=bridge=br0,model=virtio \
    –noautoconsole \
  –hvm \
  –graphics vnc

os='debian9';
virt-install –import –name $os     \
–ram 2048     \
–vcpu 2     \
–disk path=/var/lib/libvirt/images/$os-vm1.qcow2,format=qcow2     \
–os-variant debian9     –network=bridge=br0,model=virtio     \
–noautoconsole \
–hvm \
–graphics vnc


To deploy more just change the virtual machine type in os variable and modify the –os-variant variable to match the distribution name, to get the correct –os-variant variables that can be passed use osinfo-query below is output of the cmd:

root@jeremiah:/home/hipo/kvm# osinfo-query os
 Short ID             | Name                                               | Version  | ID                                      
———————-+—————————————————-+———-+—————————————–
 altlinux1.0          | Mandrake RE Spring 2001                            | 1.0      | http://altlinux.org/altlinux/1.0        
 altlinux2.0          | ALT Linux 2.0                                      | 2.0      | http://altlinux.org/altlinux/2.0        
 altlinux2.2          | ALT Linux 2.2                                      | 2.2      | http://altlinux.org/altlinux/2.2        
 altlinux2.4          | ALT Linux 2.4                                      | 2.4      | http://altlinux.org/altlinux/2.4        
 altlinux3.0          | ALT Linux 3.0                                      | 3.0      | http://altlinux.org/altlinux/3.0        
 altlinux4.0          | ALT Linux 4.0                                      | 4.0      | http://altlinux.org/altlinux/4.0        
 altlinux4.1          | ALT Linux 4.1                                      | 4.1      | http://altlinux.org/altlinux/4.1        
 altlinux5.0          | ALT Linux 5.0                                      | 5.0      | http://altlinux.org/altlinux/5.0        
 altlinux6.0          | ALT Linux 6.0                                      | 6.0      | http://altlinux.org/altlinux/6.0        
 altlinux7.0          | ALT Linux 7.0                                      | 7.0      | http://altlinux.org/altlinux/7.0        
 centos6.0            | CentOS 6.0                                         | 6.0      | http://centos.org/centos/6.0            
 centos6.1            | CentOS 6.1                                         | 6.1      | http://centos.org/centos/6.1            
 centos6.2            | CentOS 6.2                                         | 6.2      | http://centos.org/centos/6.2            
 centos6.3            | CentOS 6.3                                         | 6.3      | http://centos.org/centos/6.3            
 centos6.4            | CentOS 6.4                                         | 6.4      | http://centos.org/centos/6.4            
 centos6.5            | CentOS 6.5                                         | 6.5      | http://centos.org/centos/6.5            
 centos6.6            | CentOS 6.6                                         | 6.6      | http://centos.org/centos/6.6            
 centos6.7            | CentOS 6.7                                         | 6.7      | http://centos.org/centos/6.7            
 centos6.8            | CentOS 6.8                                         | 6.8      | http://centos.org/centos/6.8            
 centos6.9            | CentOS 6.9                                         | 6.9      | http://centos.org/centos/6.9            
 centos7.0            | CentOS 7.0                                         | 7.0      | http://centos.org/centos/7.0            
 debian1.1            | Debian Buzz                                        | 1.1      | http://debian.org/debian/1.1            
 debian1.2            | Debian Rex                                         | 1.2      | http://debian.org/debian/1.2            
 debian1.3            | Debian Bo                                          | 1.3      | http://debian.org/debian/1.3            
 debian2.0            | Debian Hamm                                        | 2.0      | http://debian.org/debian/2.0            
 debian2.1            | Debian Slink                                       | 2.1      | http://debian.org/debian/2.1            
 debian2.2            | Debian Potato                                      | 2.2      | http://debian.org/debian/2.2            
 debian3              | Debian Woody                                       | 3        | http://debian.org/debian/3              
 debian3.1            | Debian Sarge                                       | 3.1      | http://debian.org/debian/3.1            
 debian4              | Debian Etch                                        | 4        | http://debian.org/debian/4              
 debian5              | Debian Lenny                                       | 5        | http://debian.org/debian/5              
 debian6              | Debian Squeeze                                     | 6        | http://debian.org/debian/6              
 debian7              | Debian Wheezy                                      | 7        | http://debian.org/debian/7              
 debian8              | Debian Jessie                                      | 8        | http://debian.org/debian/8              
 debian9              | Debian Stretch                                     | 9        | http://debian.org/debian/9              
 debiantesting        | Debian Testing                                     | testing  | http://debian.org/debian/testing        
 fedora-unknown       | Fedora                                             | unknown  | http://fedoraproject.org/fedora/unknown
 fedora1              | Fedora Core 1                                      | 1        | http://fedoraproject.org/fedora/1       
 fedora10             | Fedora 10                                          | 10       | http://fedoraproject.org/fedora/10      
 fedora11             | Fedora 11                                          | 11       | http://fedoraproject.org/fedora/11      
 fedora12             | Fedora 12                                          | 12       | http://fedoraproject.org/fedora/12      
 fedora13             | Fedora 13                                          | 13       | http://fedoraproject.org/fedora/13      
 fedora14             | Fedora 14                                          | 14       | http://fedoraproject.org/fedora/14      
 fedora15             | Fedora 15                                          | 15       | http://fedoraproject.org/fedora/15      
 fedora16             | Fedora 16                                          | 16       | http://fedoraproject.org/fedora/16      
 fedora17             | Fedora 17                                          | 17       | http://fedoraproject.org/fedora/17      
 fedora18             | Fedora 18                                          | 18       | http://fedoraproject.org/fedora/18      
 fedora19             | Fedora 19                                          | 19       | http://fedoraproject.org/fedora/19      
 fedora2              | Fedora Core 2                                      | 2        | http://fedoraproject.org/fedora/2       
 fedora20             | Fedora 20                                          | 20       | http://fedoraproject.org/fedora/20      
 fedora21             | Fedora 21                                          | 21       | http://fedoraproject.org/fedora/21      
 fedora22             | Fedora 22                                          | 22       | http://fedoraproject.org/fedora/22      
 fedora23             | Fedora 23                                          | 23       | http://fedoraproject.org/fedora/23      
 fedora24             | Fedora 24                                          | 24       | http://fedoraproject.org/fedora/24      
 fedora25             | Fedora 25                                          | 25       | http://fedoraproject.org/fedora/25      
 fedora26             | Fedora 26                                          | 26       | http://fedoraproject.org/fedora/26      
 fedora3              | Fedora Core 3                                      | 3        | http://fedoraproject.org/fedora/3       
 fedora4              | Fedora Core 4                                      | 4        | http://fedoraproject.org/fedora/4       
 fedora5              | Fedora Core 5                                      | 5        | http://fedoraproject.org/fedora/5       
 fedora6              | Fedora Core 6                                      | 6        | http://fedoraproject.org/fedora/6       
 fedora7              | Fedora 7                                           | 7        | http://fedoraproject.org/fedora/7       
 fedora8              | Fedora 8                                           | 8        | http://fedoraproject.org/fedora/8       
 fedora9              | Fedora 9                                           | 9        | http://fedoraproject.org/fedora/9       
 freebsd1.0           | FreeBSD 1.0                                        | 1.0      | http://freebsd.org/freebsd/1.0          
 freebsd10.0          | FreeBSD 10.0                                       | 10.0     | http://freebsd.org/freebsd/10.0         
 freebsd10.1          | FreeBSD 10.1                                       | 10.1     | http://freebsd.org/freebsd/10.1         
 freebsd10.2          | FreeBSD 10.2                                       | 10.2     | http://freebsd.org/freebsd/10.2         
 freebsd10.3          | FreeBSD 10.3                                       | 10.3     | http://freebsd.org/freebsd/10.3         
 freebsd10.4          | FreeBSD 10.4                                       | 10.4     | http://freebsd.org/freebsd/10.4         
 freebsd11.0          | FreeBSD 11.0                                       | 11.0     | http://freebsd.org/freebsd/11.0         
 freebsd11.1          | FreeBSD 11.1                                       | 11.1     | http://freebsd.org/freebsd/11.1         
 freebsd2.0           | FreeBSD 2.0                                        | 2.0      | http://freebsd.org/freebsd/2.0          
 freebsd2.0.5         | FreeBSD 2.0.5                                      | 2.0.5    | http://freebsd.org/freebsd/2.0.5        
 freebsd2.2.8         | FreeBSD 2.2.8                                      | 2.2.8    | http://freebsd.org/freebsd/2.2.8        
 freebsd2.2.9         | FreeBSD 2.2.9                                      | 2.2.9    | http://freebsd.org/freebsd/2.2.9        
 freebsd3.0           | FreeBSD 3.0                                        | 3.0      | http://freebsd.org/freebsd/3.0          
 freebsd3.2           | FreeBSD 3.2                                        | 3.2      | http://freebsd.org/freebsd/3.2          
 freebsd4.0           | FreeBSD 4.0                                        | 4.0      | http://freebsd.org/freebsd/4.0          
 freebsd4.1           | FreeBSD 4.1                                        | 4.1      | http://freebsd.org/freebsd/4.1          
 freebsd4.10          | FreeBSD 4.10                                       | 4.10     | http://freebsd.org/freebsd/4.10         
 freebsd4.11          | FreeBSD 4.11                                       | 4.11     | http://freebsd.org/freebsd/4.11         
 freebsd4.2           | FreeBSD 4.2                                        | 4.2      | http://freebsd.org/freebsd/4.2          
 freebsd4.3           | FreeBSD 4.3                                        | 4.3      | http://freebsd.org/freebsd/4.3          
 freebsd4.4           | FreeBSD 4.4                                        | 4.4      | http://freebsd.org/freebsd/4.4          
 freebsd4.5           | FreeBSD 4.5                                        | 4.5      | http://freebsd.org/freebsd/4.5          
 freebsd4.6           | FreeBSD 4.6                                        | 4.6      | http://freebsd.org/freebsd/4.6          
 freebsd4.7           | FreeBSD 4.7                                        | 4.7      | http://freebsd.org/freebsd/4.7          
 freebsd4.8           | FreeBSD 4.8                                        | 4.8      | http://freebsd.org/freebsd/4.8          
 freebsd4.9           | FreeBSD 4.9                                        | 4.9      | http://freebsd.org/freebsd/4.9          
 freebsd5.0           | FreeBSD 5.0                                        | 5.0      | http://freebsd.org/freebsd/5.0          
 freebsd5.1           | FreeBSD 5.1                                        | 5.1      | http://freebsd.org/freebsd/5.1          
 freebsd5.2           | FreeBSD 5.2                                        | 5.2      | http://freebsd.org/freebsd/5.2          
 freebsd5.2.1         | FreeBSD 5.2.1                                      | 5.2.1    | http://freebsd.org/freebsd/5.2.1        
 freebsd5.3           | FreeBSD 5.3                                        | 5.3      | http://freebsd.org/freebsd/5.3          
 freebsd5.4           | FreeBSD 5.4                                        | 5.4      | http://freebsd.org/freebsd/5.4          
 freebsd5.5           | FreeBSD 5.5                                        | 5.5      | http://freebsd.org/freebsd/5.5          
 freebsd6.0           | FreeBSD 6.0                                        | 6.0      | http://freebsd.org/freebsd/6.0          
 freebsd6.1           | FreeBSD 6.1                                        | 6.1      | http://freebsd.org/freebsd/6.1          
 freebsd6.2           | FreeBSD 6.2                                        | 6.2      | http://freebsd.org/freebsd/6.2          
 freebsd6.3           | FreeBSD 6.3                                        | 6.3      | http://freebsd.org/freebsd/6.3          
 freebsd6.4           | FreeBSD 6.4                                        | 6.4      | http://freebsd.org/freebsd/6.4          
 freebsd7.0           | FreeBSD 7.0                                        | 7.0      | http://freebsd.org/freebsd/7.0          
 freebsd7.1           | FreeBSD 7.1                                        | 7.1      | http://freebsd.org/freebsd/7.1          
 freebsd7.2           | FreeBSD 7.2                                        | 7.2      | http://freebsd.org/freebsd/7.2          
 freebsd7.3           | FreeBSD 7.3                                        | 7.3      | http://freebsd.org/freebsd/7.3          
 freebsd7.4           | FreeBSD 7.4                                        | 7.4      | http://freebsd.org/freebsd/7.4          
 freebsd8.0           | FreeBSD 8.0                                        | 8.0      | http://freebsd.org/freebsd/8.0          
 freebsd8.1           | FreeBSD 8.1                                        | 8.1      | http://freebsd.org/freebsd/8.1          
 freebsd8.2           | FreeBSD 8.2                                        | 8.2      | http://freebsd.org/freebsd/8.2          
 freebsd8.3           | FreeBSD 8.3                                        | 8.3      | http://freebsd.org/freebsd/8.3          
 freebsd8.4           | FreeBSD 8.4                                        | 8.4      | http://freebsd.org/freebsd/8.4          
 freebsd9.0           | FreeBSD 9.0                                        | 9.0      | http://freebsd.org/freebsd/9.0          
 freebsd9.1           | FreeBSD 9.1                                        | 9.1      | http://freebsd.org/freebsd/9.1          
 freebsd9.2           | FreeBSD 9.2                                        | 9.2      | http://freebsd.org/freebsd/9.2          
 freebsd9.3           | FreeBSD 9.3                                        | 9.3      | http://freebsd.org/freebsd/9.3          
 freedos1.2           | FreeDOS 1.2                                        | 1.2      | http://freedos.org/freedos/1.2          
 gnome-continuous-3.10 | GNOME 3.10                                         | 3.10     | http://gnome.org/gnome-continuous/3.10  
 gnome-continuous-3.12 | GNOME 3.12                                         | 3.12     | http://gnome.org/gnome-continuous/3.12  
 gnome-continuous-3.14 | GNOME 3.14                                         | 3.14     | http://gnome.org/gnome-continuous/3.14  
 gnome3.6             | GNOME 3.6                                          | 3.6      | http://gnome.org/gnome/3.6              
 gnome3.8             | GNOME 3.8                                          | 3.8      | http://gnome.org/gnome/3.8              
 macosx10.0           | MacOS X Cheetah                                    | 10.0     | http://apple.com/macosx/10.0            
 macosx10.1           | MacOS X Puma                                       | 10.1     | http://apple.com/macosx/10.1            
 macosx10.2           | MacOS X Jaguar                                     | 10.2     | http://apple.com/macosx/10.2            
 macosx10.3           | MacOS X Panther                                    | 10.3     | http://apple.com/macosx/10.3            
 macosx10.4           | MacOS X Tiger                                      | 10.4     | http://apple.com/macosx/10.4            
 macosx10.5           | MacOS X Leopard                                    | 10.5     | http://apple.com/macosx/10.5            
 macosx10.6           | MacOS X Snow Leopard                               | 10.6     | http://apple.com/macosx/10.6            
 macosx10.7           | MacOS X Lion                                       | 10.7     | http://apple.com/macosx/10.7            
 mageia1              | Mageia 1                                           | 1        | http://mageia.org/mageia/1              
 mageia2              | Mageia 2                                           | 2        | http://mageia.org/mageia/2              
 mageia3              | Mageia 3                                           | 3        | http://mageia.org/mageia/3              
 mageia4              | Mageia 4                                           | 4        | http://mageia.org/mageia/4              
 mageia5              | Mageia 5                                           | 5        | http://mageia.org/mageia/5              
 mageia6              | Mageia 6                                           | 6        | http://mageia.org/mageia/6              
 mandrake10.0         | Mandrake Linux 10.0                                | 10.0     | http://mandriva.com/mandrake/10.0       
 mandrake10.1         | Mandrake Linux 10.1                                | 10.1     | http://mandriva.com/mandrake/10.1       
 mandrake10.2         | Mandrake Linux 10.2                                | 10.2     | http://mandriva.com/mandrake/10.2       
 mandrake5.1          | Mandrake Linux 5.1                                 | 5.1      | http://mandriva.com/mandrake/5.1        
 mandrake5.2          | Mandrake Linux 5.2                                 | 5.2      | http://mandriva.com/mandrake/5.2        
 mandrake5.3          | Mandrake Linux 5.3                                 | 5.3      | http://mandriva.com/mandrake/5.3        
 mandrake6.0          | Mandrake Linux 6.0                                 | 6.0      | http://mandriva.com/mandrake/6.0        
 mandrake6.1          | Mandrake Linux 6.1                                 | 6.1      | http://mandriva.com/mandrake/6.1        
 mandrake7.0          | Mandrake Linux 7.0                                 | 7.0      | http://mandriva.com/mandrake/7.0        
 mandrake7.1          | Mandrake Linux 7.1                                 | 7.1      | http://mandriva.com/mandrake/7.1        
 mandrake7.2          | Mandrake Linux 7.2                                 | 7.2      | http://mandriva.com/mandrake/7.2        
 mandrake8.0          | Mandrake Linux 8.0                                 | 8.0      | http://mandriva.com/mandrake/8.0        
 mandrake8.1          | Mandrake Linux 8.1                                 | 8.1      | http://mandriva.com/mandrake/8.1        
 mandrake8.2          | Mandrake Linux 8.2                                 | 8.2      | http://mandriva.com/mandrake/8.2        
 mandrake9.0          | Mandrake Linux 9.0                                 | 9.0      | http://mandriva.com/mandrake/9.0        
 mandrake9.1          | Mandrake Linux 9.1                                 | 9.1      | http://mandriva.com/mandrake/9.1        
 mandrake9.2          | Mandrake Linux 9.2                                 | 9.2      | http://mandriva.com/mandrake/9.2        
 mandriva2006.0       | Mandriva Linux 2006.0                              | 2006.0   | http://mandriva.com/mandriva/2006.0     
 mandriva2007         | Mandriva Linux 2007                                | 2007     | http://mandriva.com/mandriva/2007       
 mandriva2007.1       | Mandriva Linux 2007 Spring                         | 2007.1   | http://mandriva.com/mandriva/2007.1     
 mandriva2008.0       | Mandriva Linux 2008                                | 2008.0   | http://mandriva.com/mandriva/2008.0     
 mandriva2008.1       | Mandriva Linux 2008 Spring                         | 2008.1   | http://mandriva.com/mandriva/2008.1     
 mandriva2009.0       | Mandriva Linux 2009                                | 2009.0   | http://mandriva.com/mandriva/2009.0     
 mandriva2009.1       | Mandriva Linux 2009 Spring                         | 2009.1   | http://mandriva.com/mandriva/2009.1     
 mandriva2010.0       | Mandriva Linux 2010                                | 2010.0   | http://mandriva.com/mandriva/2010.0     
 mandriva2010.1       | Mandriva Linux 2010 Spring                         | 2010.1   | http://mandriva.com/mandriva/2010.1     
 mandriva2010.2       | Mandriva Linux 2010.2                              | 2010.2   | http://mandriva.com/mandriva/2010.2     
 mandriva2011         | Mandriva Linux 2011                                | 2011     | http://mandriva.com/mandriva/2011       
 mbs1.0               | Mandriva Business Server 1.0                       | 1.0      | http://mandriva.com/mbs/1.0             
 mes5                 | Mandriva Enterprise Server 5.0                     | 5.0      | http://mandriva.com/mes/5.0             
 mes5.1               | Mandriva Enterprise Server 5.1                     | 5.1      | http://mandriva.com/mes/5.1             
 msdos6.22            | Microsoft MS-DOS 6.22                              | 6.22     | http://microsoft.com/msdos/6.22         
 netbsd0.8            | NetBSD 0.8                                         | 0.8      | http://netbsd.org/netbsd/0.8            
 netbsd0.9            | NetBSD 0.9                                         | 0.9      | http://netbsd.org/netbsd/0.9            
 netbsd1.0            | NetBSD 1.0                                         | 1.0      | http://netbsd.org/netbsd/1.0            
 netbsd1.1            | NetBSD 1.1                                         | 1.1      | http://netbsd.org/netbsd/1.1            
 netbsd1.2            | NetBSD 1.2                                         | 1.2      | http://netbsd.org/netbsd/1.2            
 netbsd1.3            | NetBSD 1.3                                         | 1.3      | http://netbsd.org/netbsd/1.3            
 netbsd1.4            | NetBSD 1.4                                         | 1.4      | http://netbsd.org/netbsd/1.4            
 netbsd1.5            | NetBSD 1.5                                         | 1.5      | http://netbsd.org/netbsd/1.5            
 netbsd1.6            | NetBSD 1.6                                         | 1.6      | http://netbsd.org/netbsd/1.6            
 netbsd2.0            | NetBSD 2.0                                         | 2.0      | http://netbsd.org/netbsd/2.0            
 netbsd3.0            | NetBSD 3.0                                         | 3.0      | http://netbsd.org/netbsd/3.0            
 netbsd4.0            | NetBSD 4.0                                         | 4.0      | http://netbsd.org/netbsd/4.0            
 netbsd5.0            | NetBSD 5.0                                         | 5.0      | http://netbsd.org/netbsd/5.0            
 netbsd5.1            | NetBSD 5.1                                         | 5.1      | http://netbsd.org/netbsd/5.1            
 netbsd6.0            | NetBSD 6.0                                         | 6.0      | http://netbsd.org/netbsd/6.0            
 netbsd6.1            | NetBSD 6.1                                         | 6.1      | http://netbsd.org/netbsd/6.1            
 netbsd7.0            | NetBSD 7.0                                         | 7.0      | http://netbsd.org/netbsd/7.0            
 netbsd7.1            | NetBSD 7.1                                         | 7.1      | http://netbsd.org/netbsd/7.1            
 netbsd7.1.1          | NetBSD 7.1.1                                       | 7.1.1    | http://netbsd.org/netbsd/7.1.1          
 netware4             | Novell Netware 4                                   | 4        | http://novell.com/netware/4             
 netware5             | Novell Netware 5                                   | 5        | http://novell.com/netware/5             
 netware6             | Novell Netware 6                                   | 6        | http://novell.com/netware/6             
 openbsd4.2           | OpenBSD 4.2                                        | 4.2      | http://openbsd.org/openbsd/4.2          
 openbsd4.3           | OpenBSD 4.3                                        | 4.3      | http://openbsd.org/openbsd/4.3          
 openbsd4.4           | OpenBSD 4.4                                        | 4.4      | http://openbsd.org/openbsd/4.4          
 openbsd4.5           | OpenBSD 4.5                                        | 4.5      | http://openbsd.org/openbsd/4.5          
 openbsd4.8           | OpenBSD 4.8                                        | 4.8      | http://openbsd.org/openbsd/4.8          
 openbsd4.9           | OpenBSD 4.9                                        | 4.9      | http://openbsd.org/openbsd/4.9          
 openbsd5.0           | OpenBSD 5.0                                        | 5.0      | http://openbsd.org/openbsd/5.0          
 openbsd5.1           | OpenBSD 5.1                                        | 5.1      | http://openbsd.org/openbsd/5.1          
 openbsd5.2           | OpenBSD 5.2                                        | 5.2      | http://openbsd.org/openbsd/5.2          
 openbsd5.3           | OpenBSD 5.3                                        | 5.3      | http://openbsd.org/openbsd/5.3          
 openbsd5.4           | OpenBSD 5.4                                        | 5.4      | http://openbsd.org/openbsd/5.4          
 openbsd5.5           | OpenBSD 5.5                                        | 5.5      | http://openbsd.org/openbsd/5.5          
 openbsd5.6           | OpenBSD 5.6                                        | 5.6      | http://openbsd.org/openbsd/5.6          
 openbsd5.7           | OpenBSD 5.7                                        | 5.7      | http://openbsd.org/openbsd/5.7          
 openbsd5.8           | OpenBSD 5.8                                        | 5.8      | http://openbsd.org/openbsd/5.8          
 openbsd5.9           | OpenBSD 5.9                                        | 5.9      | http://openbsd.org/openbsd/5.9          
 openbsd6.0           | OpenBSD 6.0                                        | 6.0      | http://openbsd.org/openbsd/6.0          
 openbsd6.1           | OpenBSD 6.1                                        | 6.1      | http://openbsd.org/openbsd/6.1          
 openbsd6.2           | OpenBSD 6.2                                        | 6.2      | http://openbsd.org/openbsd/6.2          
 opensolaris2009.06   | OpenSolaris 2009.06                                | 2009.06  | http://sun.com/opensolaris/2009.06      
 opensuse-factory     | openSUSE                                           | factory  | http://opensuse.org/opensuse/factory    
 opensuse-unknown     | openSUSE                                           | unknown  | http://opensuse.org/opensuse/unknown    
 opensuse10.2         | openSUSE 10.2                                      | 10.2     | http://opensuse.org/opensuse/10.2       
 opensuse10.3         | openSUSE 10.3                                      | 10.3     | http://opensuse.org/opensuse/10.3       
 opensuse11.0         | openSUSE 11.0                                      | 11.0     | http://opensuse.org/opensuse/11.0       
 opensuse11.1         | openSUSE 11.1                                      | 11.1     | http://opensuse.org/opensuse/11.1       
 opensuse11.2         | openSUSE 11.2                                      | 11.2     | http://opensuse.org/opensuse/11.2       
 opensuse11.3         | openSUSE 11.3                                      | 11.3     | http://opensuse.org/opensuse/11.3       
 opensuse11.4         | openSUSE 11.4                                      | 11.4     | http://opensuse.org/opensuse/11.4       
 opensuse12.1         | openSUSE 12.1                                      | 12.1     | http://opensuse.org/opensuse/12.1       
 opensuse12.2         | openSUSE 12.2                                      | 12.2     | http://opensuse.org/opensuse/12.2       
 opensuse12.3         | openSUSE 12.3                                      | 12.3     | http://opensuse.org/opensuse/12.3       
 opensuse13.1         | openSUSE 13.1                                      | 13.1     | http://opensuse.org/opensuse/13.1       
 opensuse13.2         | openSUSE 13.2                                      | 13.2     | http://opensuse.org/opensuse/13.2       
 opensuse42.1         | openSUSE Leap 42.1                                 | 42.1     | http://opensuse.org/opensuse/42.1       
 opensuse42.2         | openSUSE Leap 42.2                                 | 42.2     | http://opensuse.org/opensuse/42.2       
 opensuse42.3         | openSUSE Leap 42.3                                 | 42.3     | http://opensuse.org/opensuse/42.3       
 opensusetumbleweed   | openSUSE Tumbleweed                                | tumbleweed | http://opensuse.org/opensuse/tumbleweed
 rhel-atomic-7.0      | Red Hat Enterprise Linux Atomic Host 7.0           | 7.0      | http://redhat.com/rhel-atomic/7.0       
 rhel-atomic-7.1      | Red Hat Enterprise Linux Atomic Host 7.1           | 7.1      | http://redhat.com/rhel-atomic/7.1       
 rhel-atomic-7.2      | Red Hat Enterprise Linux Atomic Host 7.2           | 7.2      | http://redhat.com/rhel-atomic/7.2       
 rhel2.1              | Red Hat Enterprise Linux 2.1                       | 2.1      | http://redhat.com/rhel/2.1              
 rhel2.1.1            | Red Hat Enterprise Linux 2.1 Update 1  
/etc/bind/masters/elinvent.com            | 2.1.1    | http://redhat.com/rhel/2.1.1            
 rhel2.1.2            | Red Hat Enterprise Linux 2.1 Update 2              | 2.1.2    | http://redhat.com/rhel/2.1.2            
 rhel2.1.3            | Red Hat Enterprise Linux 2.1 Update 3              | 2.1.3    | http://redhat.com/rhel/2.1.3            
 rhel2.1.4            | Red Hat Enterprise Linux 2.1 Update 4              | 2.1.4    | http://redhat.com/rhel/2.1.4            
 rhel2.1.5            | Red Hat Enterprise Linux 2.1 Update 5              | 2.1.5    | http://redhat.com/rhel/2.1.5            
 rhel2.1.6            | Red Hat Enterprise Linux 2.1 Update 6              | 2.1.6    | http://redhat.com/rhel/2.1.6            
 rhel2.1.7            | Red Hat Enterprise Linux 2.1 Update 7              | 2.1.7    | http://redhat.com/rhel/2.1.7            
 rhel3                | Red Hat Enterprise Linux 3                         | 3        | http://redhat.com/rhel/3                
 rhel3.1              | Red Hat Enterprise Linux 3 Update 1                | 3.1      | http://redhat.com/rhel/3.1              
 rhel3.2              | Red Hat Enterprise Linux 3 Update 2                | 3.2      | http://redhat.com/rhel/3.2              
 rhel3.3              | Red Hat Enterprise Linux 3 Update 3                | 3.3      | http://redhat.com/rhel/3.3              
 rhel3.4              | Red Hat Enterprise Linux 3 Update 4                | 3.4      | http://redhat.com/rhel/3.4              
 rhel3.5              | Red Hat Enterprise Linux 3 Update 5                | 3.5      | http://redhat.com/rhel/3.5              
 rhel3.6              | Red Hat Enterprise Linux 3 Update 6                | 3.6      | http://redhat.com/rhel/3.6              
 rhel3.7              | Red Hat Enterprise Linux 3 Update 7                | 3.7      | http://redhat.com/rhel/3.7              
 rhel3.8              | Red Hat Enterprise Linux 3 Update 8                | 3.8      | http://redhat.com/rhel/3.8              
 rhel3.9              | Red Hat Enterprise Linux 3 Update 9                | 3.9      | http://redhat.com/rhel/3.9              
 rhel4.0              | Red Hat Enterprise Linux 4.0                       | 4.0      | http://redhat.com/rhel/4.0              
 rhel4.1              | Red Hat Enterprise Linux 4.1                       | 4.1      | http://redhat.com/rhel/4.1              
 rhel4.2              | Red Hat Enterprise Linux 4.2                       | 4.2      | http://redhat.com/rhel/4.2              
 rhel4.3              | Red Hat Enterprise Linux 4.3                       | 4.3      | http://redhat.com/rhel/4.3              
 rhel4.4              | Red Hat Enterprise Linux 4.4                       | 4.4      | http://redhat.com/rhel/4.4              
 rhel4.5              | Red Hat Enterprise Linux 4.5                       | 4.5      | http://redhat.com/rhel/4.5              
 rhel4.6              | Red Hat Enterprise Linux 4.6                       | 4.6      | http://redhat.com/rhel/4.6              
 rhel4.7              | Red Hat Enterprise Linux 4.7                       | 4.7      | http://redhat.com/rhel/4.7              
 rhel4.8              | Red Hat Enterprise Linux 4.8                       | 4.8      | http://redhat.com/rhel/4.8              
 rhel4.9              | Red Hat Enterprise Linux 4.9                       | 4.9      | http://redhat.com/rhel/4.9              
 rhel5.0              | Red Hat Enterprise Linux 5.0                       | 5.0      | http://redhat.com/rhel/5.0              
 rhel5.1              | Red Hat Enterprise Linux 5.1                       | 5.1      | http://redhat.com/rhel/5.1              
 rhel5.10             | Red Hat Enterprise Linux 5.10                      | 5.10     | http://redhat.com/rhel/5.10             
 rhel5.11             | Red Hat Enterprise Linux 5.11                      | 5.11     | http://redhat.com/rhel/5.11             
 rhel5.2              | Red Hat Enterprise Linux 5.2                       | 5.2      | http://redhat.com/rhel/5.2              
 rhel5.3              | Red Hat Enterprise Linux 5.3                       | 5.3      | http://redhat.com/rhel/5.3              
 rhel5.4              | Red Hat Enterprise Linux 5.4                       | 5.4      | http://redhat.com/rhel/5.4              
 rhel5.5              | Red Hat Enterprise Linux 5.5                       | 5.5      | http://redhat.com/rhel/5.5              
 rhel5.6              | Red Hat Enterprise Linux 5.6                       | 5.6      | http://redhat.com/rhel/5.6              
 rhel5.7              | Red Hat Enterprise Linux 5.7                       | 5.7      | http://redhat.com/rhel/5.7              
 rhel5.8              | Red Hat Enterprise Linux 5.8                       | 5.8      | http://redhat.com/rhel/5.8              
 rhel5.9              | Red Hat Enterprise Linux 5.9                       | 5.9      | http://redhat.com/rhel/5.9              
 rhel6.0              | Red Hat Enterprise Linux 6.0                       | 6.0      | http://redhat.com/rhel/6.0              
 rhel6.1              | Red Hat Enterprise Linux 6.1                       | 6.1      | http://redhat.com/rhel/6.1              
 rhel6.2              | Red Hat Enterprise Linux 6.2                       | 6.2      | http://redhat.com/rhel/6.2              
 rhel6.3              | Red Hat Enterprise Linux 6.3                       | 6.3      | http://redhat.com/rhel/6.3              
 rhel6.4              | Red Hat Enterprise Linux 6.4                       | 6.4      | http://redhat.com/rhel/6.4              
 rhel6.5              | Red Hat Enterprise Linux 6.5                       | 6.5      | http://redhat.com/rhel/6.5              
 rhel6.6              | Red Hat Enterprise Linux 6.6                       | 6.6      | http://redhat.com/rhel/6.6              
 rhel6.7              | Red Hat Enterprise Linux 6.7                       | 6.7      | http://redhat.com/rhel/6.7              
 rhel6.8              | Red Hat Enterprise Linux 6.8                       | 6.8      | http://redhat.com/rhel/6.8              
 rhel6.9              | Red Hat Enterprise Linux 6.9                       | 6.9      | http://redhat.com/rhel/6.9              
 rhel7.0              | Red Hat Enterprise Linux 7.0                       | 7.0      | http://redhat.com/rhel/7.0              
 rhel7.1              | Red Hat Enterprise Linux 7.1                       | 7.1      | http://redhat.com/rhel/7.1              
 rhel7.2              | Red Hat Enterprise Linux 7.2                       | 7.2      | http://redhat.com/rhel/7.2              
 rhel7.3              | Red Hat Enterprise Linux 7.3                       | 7.3      | http://redhat.com/rhel/7.3              
 rhel7.4              | Red Hat Enterprise Linux 7.4                       | 7.4      | http://redhat.com/rhel/7.4              
 rhl1.0               | Red Hat Linux 1.0                                  | 1.0      | http://redhat.com/rhl/1.0               
 rhl1.1               | Red Hat Linux 1.1                                  | 1.1      | http://redhat.com/rhl/1.1               
 rhl2.0               | Red Hat Linux 2.0                                  | 2.0      | http://redhat.com/rhl/2.0               
 rhl2.1               | Red Hat Linux 2.1                                  | 2.1      | http://redhat.com/rhl/2.1               
 rhl3.0.3             | Red Hat Linux 3.0.3                                | 3.0.3    | http://redhat.com/rhl/3.0.3             
 rhl4.0               | Red Hat Linux 4.0                                  | 4.0      | http://redhat.com/rhl/4.0               
 rhl4.1               | Red Hat Linux 4.1                                  | 4.1      | http://redhat.com/rhl/4.1               
 rhl4.2               | Red Hat Linux 4.2                                  | 4.2      | http://redhat.com/rhl/4.2               
 rhl5.0               | Red Hat Linux 5.0                                  | 5.0      | http://redhat.com/rhl/5.0               
 rhl5.1               | Red Hat Linux 5.1                                  | 5.1      | http://redhat.com/rhl/5.1               
 rhl5.2               | Red Hat Linux 5.2                                  | 5.2      | http://redhat.com/rhl/5.2               
 rhl6.0               | Red Hat Linux 6.0                                  | 6.0      | http://redhat.com/rhl/6.0               
 rhl6.1               | Red Hat Linux 6.1                                  | 6.1      | http://redhat.com/rhl/6.1               
 rhl6.2               | Red Hat Linux 6.2                                  | 6.2      | http://redhat.com/rhl/6.2               
 rhl7                 | Red Hat Linux 7                                    | 7        | http://redhat.com/rhl/7                 
 rhl7.1               | Red Hat Linux 7.1                                  | 7.1      | http://redhat.com/rhl/7.1               
 rhl7.2               | Red Hat Linux 7.2                                  | 7.2      | http://redhat.com/rhl/7.2               
 rhl7.3               | Red Hat Linux 7.3                                  | 7.3      | http://redhat.com/rhl/7.3               
 rhl8.0               | Red Hat Linux 8.0                                  | 8.0      | http://redhat.com/rhl/8.0               
 rhl9                 | Red Hat Linux 9                                    | 9        | http://redhat.com/rhl/9                 
 sled10               | SUSE Linux Enterprise Desktop 10                   | 10       | http://suse.com/sled/10                 
 sled10sp1            | SUSE Linux Enterprise Desktop 10 SP1               | 10.1     | http://suse.com/sled/10.1               
 sled10sp2            | SUSE Linux Enterprise Desktop 10 SP2               | 10.2     | http://suse.com/sled/10.2               
 sled10sp3            | SUSE Linux Enterprise Desktop 10 SP3               | 10.3     | http://suse.com/sled/10.3               
 sled10sp4            | SUSE Linux Enterprise Desktop 10 SP4               | 10.4     | http://suse.com/sled/10.4               
 sled11               | SUSE Linux Enterprise Desktop 11                   | 11       | http://suse.com/sled/11                 
 sled11sp1            | SUSE Linux Enterprise Desktop 11 SP1               | 11.1     | http://suse.com/sled/11.1               
 sled11sp2            | SUSE Linux Enterprise Desktop 11 SP2               | 11.2     | http://suse.com/sled/11.2               
 sled11sp3            | SUSE Linux Enterprise Desktop 11 SP3               | 11.3     | http://suse.com/sled/11.3               
 sled11sp4            | SUSE Linux Enterprise Desktop 11 SP4               | 11.4     | http://suse.com/sled/11.4               
 sled12               | SUSE Linux Enterprise Desktop 12                   | 12       | http://suse.com/sled/12                 
 sled12sp1            | SUSE Linux Enterprise Desktop 12 SP1               | 12.1     | http://suse.com/sled/12.1               
 sled12sp2            | SUSE Linux Enterprise Desktop 12 SP2               | 12.2     | http://suse.com/sled/12.2               
 sled9                | SUSE Linux Enterprise Desktop 9                    | 9        | http://suse.com/sled/9                  
 sles10               | SUSE Linux Enterprise Server 10            
/etc/bind/masters/elinvent.com        | 10       | http://suse.com/sles/10                 
 sles10sp1            | SUSE Linux Enterprise Server 10 SP1                | 10.1     | http://suse.com/sles/10.1               
 sles10sp2            | SUSE Linux Enterprise Server 10 SP2                | 10.2     | http://suse.com/sles/10.2               
 sles10sp3            | SUSE Linux Enterprise Server 10 SP3                | 10.3     | http://suse.com/sles/10.3               
 sles10sp4            | SUSE Linux Enterprise Server 10 SP4                | 10.4     | http://suse.com/sles/10.4               
 sles11               | SUSE Linux Enterprise Server 11                    | 11       | http://suse.com/sles/11                 
 sles11sp1            | SUSE Linux Enterprise Server 11 SP1                | 11.1     | http://suse.com/sles/11.1               
 sles11sp2            | SUSE Linux Enterprise Server 11 SP2                | 11.2     | http://suse.com/sles/11.2               
 sles11sp3            | SUSE Linux Enterprise Server 11 SP3                | 11.3     | http://suse.com/sles/11.3               
 sles11sp4            | SUSE Linux Enterprise Server 11 SP4                | 11.4     | http://suse.com/sles/11.4               
 sles12               | SUSE Linux Enterprise Server 12                    | 12       | http://suse.com/sles/12                 
 sles12sp1            | SUSE Linux Enterprise Server 12 SP1                | 12.1     | http://suse.com/sles/12.1               
 sles12sp2            | SUSE Linux Enterprise Server 12 SP2                | 12.2     | http://suse.com/sles/12.2               
 sles9                | SUSE Linux Enterprise Server 9                     | 9        | http://suse.com/sles/9                  
 solaris10            | Solaris 10                                         | 10       | http://sun.com/solaris/10               
 solaris11            | Oracle Solaris 11                                  | 11       | http://oracle.com/solaris/11            
 solaris9             | Solaris 9                                          | 9        | http://sun.com/solaris/9                
 ubuntu10.04          | Ubuntu 10.04 LTS                                   | 10.04    | http://ubuntu.com/ubuntu/10.04          
 ubuntu10.10          | Ubuntu 10.10                                       | 10.10    | http://ubuntu.com/ubuntu/10.10          
 ubuntu11.04          | Ubuntu 11.04                                       | 11.04    | http://ubuntu.com/ubuntu/11.04          
 ubuntu11.10          | Ubuntu 11.10                                       | 11.10    | http://ubuntu.com/ubuntu/11.10          
 ubuntu12.04          | Ubuntu 12.04 LTS                                   | 12.04    | http://ubuntu.com/ubuntu/12.04          
 ubuntu12.10          | Ubuntu 12.10                                       | 12.10    | http://ubuntu.com/ubuntu/12.10          
 ubuntu13.04          | Ubuntu 13.04                                       | 13.04    | http://ubuntu.com/ubuntu/13.04          
 ubuntu13.10          | Ubuntu 13.10                                       | 13.10    | http://ubuntu.com/ubuntu/13.10          
 ubuntu14.04          | Ubuntu 14.04 LTS                                   | 14.04    | http://ubuntu.com/ubuntu/14.04          
 ubuntu14.10          | Ubuntu 14.10                                       | 14.10    | http://ubuntu.com/ubuntu/14.10          
 ubuntu15.04          | Ubuntu 15.04                                       | 15.04    | http://ubuntu.com/ubuntu/15.04          
 ubuntu15.10          | Ubuntu 15.10                                       | 15.10    | http://ubuntu.com/ubuntu/15.10          
 ubuntu16.04          | Ubuntu 16.04                                       | 16.04    | http://ubuntu.com/ubuntu/16.04          
 ubuntu16.10          | Ubuntu 16.10                                       | 16.10    | http://ubuntu.com/ubuntu/16.10          
 ubuntu17.04          | Ubuntu 17.04                                       | 17.04    | http://ubuntu.com/ubuntu/17.04          
 ubuntu17.10          | Ubuntu 17.10                                       | 17.10    | http://ubuntu.com/ubuntu/17.10          
 ubuntu4.10           | Ubuntu 4.10                                        | 4.10     | http://ubuntu.com/ubuntu/4.10           
 ubuntu5.04           | Ubuntu 5.04                                        | 5.04     | http://ubuntu.com/ubuntu/5.04           
 ubuntu5.10           | Ubuntu 5.10                                        | 5.10     | http://ubuntu.com/ubuntu/5.10           
 ubuntu6.06           | Ubuntu 6.06 LTS                                    | 6.06     | http://ubuntu.com/ubuntu/6.06           
 ubuntu6.10           | Ubuntu 6.10                                        | 6.10     | http://ubuntu.com/ubuntu/6.10           
 ubuntu7.04           | Ubuntu 7.04                                        | 7.04     | http://ubuntu.com/ubuntu/7.04           
 ubuntu7.10           | Ubuntu 7.10                                        | 7.10     | http://ubuntu.com/ubuntu/7.10           
 ubuntu8.04           | Ubuntu 8.04 LTS                                    | 8.04     | http://ubuntu.com/ubuntu/8.04           
 ubuntu8.10           | Ubuntu 8.10                                        | 8.10     | http://ubuntu.com/ubuntu/8.10           
 ubuntu9.04           | Ubuntu 9.04                                        | 9.04     | http://ubuntu.com/ubuntu/9.04           
 ubuntu9.10           | Ubuntu 9.10                                        | 9.10     | http://ubuntu.com/ubuntu/9.10           
 win1.0               | Microsoft Windows 1.0                              | 1.0      | http://microsoft.com/win/1.0            
 win10                | Microsoft Windows 10                               | 10.0     | http://microsoft.com/win/10             
 win2.0               | Microsoft Windows 2.0                              | 2.0      | http://microsoft.com/win/2.0            
 win2.1               | Microsoft Windows 2.1                              | 2.1      | http://microsoft.com/win/2.1            
 win2k                | Microsoft Windows 2000                             | 5.0      | http://microsoft.com/win/2k             
 win2k12              | Microsoft Windows Server 2012                      | 6.3      | http://microsoft.com/win/2k12           
 win2k12r2            | Microsoft Windows Server 2012 R2                   | 6.3      | http://microsoft.com/win/2k12r2         
 win2k3               | Microsoft Windows Server 2003                      | 5.2      | http://microsoft.com/win/2k3            
 win2k3r2             | Microsoft Windows Server 2003 R2                   | 5.2      | http://microsoft.com/win/2k3r2          
 win2k8               | Microsoft Windows Server 2008                      | 6.0      | http://microsoft.com/win/2k8            
 win2k8r2             | Microsoft Windows Server 2008 R2                   | 6.1      | http://microsoft.com/win/2k8r2          
 win3.1               | Microsoft Windows 3.1                              | 3.1      | http://microsoft.com/win/3.1            
 win7                 | Microsoft Windows 7                                | 6.1      | http://microsoft.com/win/7              
 win8                 | Microsoft Windows 8                                | 6.2      | http://microsoft.com/win/8              
 win8.1               | Microsoft Windows 8.1                              | 6.3      | http://microsoft.com/win/8.1            
 win95                | Microsoft Windows 95                               | 4.0      | http://microsoft.com/win/95             
 win98                | Microsoft Windows 98                               | 4.1      | http://microsoft.com/win/98             
 winme                | Microsoft Windows Millennium Edition               | 4.9      | http://microsoft.com/win/me             
 winnt3.1             | Microsoft Windows NT Server 3.1                    | 3.1      | http://microsoft.com/winnt/3.1          
 winnt3.5             | Microsoft Windows NT Server 3.5                    | 3.5      | http://microsoft.com/winnt/3.5          
 winnt3.51            | Microsoft Windows NT Server 3.51                   | 3.51     | http://microsoft.com/winnt/3.51         
 winnt4.0             | Microsoft Windows NT Server 4.0                    | 4.0      | http://microsoft.com/winnt/4.0          
 winvista             | Microsoft Windows Vista                            | 6.0      | http://microsoft.com/win/vista          
 winxp                | Microsoft Windows XP                               | 5.1      | http://microsoft.com/win/xp  

9. Start / Stop listed KVM Virtual Machine

root@jeremiah:~# virsh list –all
 Id    Name                           State
—————————————————-
 3     fedora-28                      running
 –     debian9                        shut off

To start debian9 linux virtual machine that is currently off

root@jeremiah:~# virsh start fedora-28
Domain fedora-28 started

root@jeremiah:/home/hipo# virsh start debian9
error: Failed to start domain debian9
error: Requested operation is not valid: network 'default' is not active

root@jeremiah:/home/hipo# virsh net-list –all
Name                 State      Autostart     Persistent
———————————————————-
br0                  active     yes           yes
default              inactive   no            yes

root@jeremiah:/home/hipo# virsh net-start default
Network default started

root@jeremiah:/home/hipo# virsh start debian9
Domain debian9 started

10. Attach to running VM with virsh or virt-manager

root@jeremiah:~# virsh list
 Id    Name                           State
—————————————————-
 1     fedora-28                      running
 3     debian9                        running

root@jeremiah:~# virsh connect debian9


Note that to make the login prompt appear you have to press enter once after the ^] connection string appears


kvm-connect-to-virtual-machine-with-virsh-command-screenshot-howto

An alternative way is to use virt-manager GUI KVM desktop management interface and click over the Virtual Machine Guest name, in same fashion like in VirtualBox.

virtual-manager-virt-manager-screenshot-with-Virtual-Machines-inside-on-Debian-Linux

virt-manager-gui-interface-connect-to-fedora-28-virtual-machine

If you have KVM running on your Linux desktop PC / notebook you can also connect via VNC with virsh command.

root@jericho:~# virsh vncdisplay centos7


Another handy thing is to expose the Virtualized Guest OS with VNC in order to be able to connect and manage installation or further Linux configuration via VNC using an SSH Tunnel with port forwarding:

$ ssh hipo@pc-freak.net -L 5901:127.0.0.1:5901

 

11.  Start / Shutdown / Suspend / Reboot (safe reboot) a VM guest machine domain

root@jericho:~# virsh shutdown debian9
root@jericho:~# virsh start fedora-28
root@jericho:~# virsh suspend debian9
root@jericho:~# virsh reboot fedora-28

12. Remove / Delete KVM Virtual Machines domain

root@jeremiah:~# virsh undefine fedora-28
root@jeremiah:~# virsh destroy fedora-28


Closing words


Using KVM to experiment with different OS distributions is really fun just like you can easily run a number of the major most popular Linux Distributions and a set of different versions. It takes few minutes to have a fully functional Linux to play with and it saves a lot of hassles when dealing with GNU / Linux and FreeBSD, doing so in Virtualbox for me prooved to be much more complicated (not to mention that often Virtualbox had an ugly bugs so even Importing an Appliance as a Guest VM with an official distro OS-es failed with weird errors.
One other very practical use of Kerkel-based Virtualization is if you want to run your servers using own Micro-Services architecture (e.g. run multiple Linux OS-es each running a separate Apache / Nginx / MySQL / PostGreSQL / Backup / Storage) etc. all of it running on a single dedicated server or a self-hosted bare-metal
There are plenty of Web Interfaces for Management KVM (proprietary and free software) that could even futher simplify the use and deploy / destory of KVM VMs.
All that makes possible running your own Linux or Web hosting provider a relatively easy task and seriously could cut business expenses and operational (maintenance) costs.

If you plan to run youw own hosting company, I can help you establish your infrastructure and advise you on the right technologies to use.

Linux: GNOME Flashback missing Desktop Icons fix – Hack to add desktop icons via gnome-shell in GNOME 3.28 onwards

Monday, September 24th, 2018

how-to-fix-workaround-gnome-3.30-missing-desktop-icons-on-linux

I just upgraded my notebook fom Debian Stretch 9.5 Linux to Buster (current Testing Debian release). All went fine except I got a lot of headaches because it seems in Buster the GNOME Flashback 3.30 which I use has removed the support for Show Desktop Icons in Nautilus because of some migration reasons of Nautilus to a newer version 4, (hopefully that would be temporary) from gnome-tweak-tool whose package now contains no binary for gnome-tweak-tool, instead an equivalent tool now is called gnome-tweaks and this tool is no longer working under Gnome Flashback but only with GNOME Classic 3.30 and the regular GNOME 3.30 launcher available from gdm3 (the Gnome Display manager).
 

1. Displaying Missing Desktop icons on GNOME version 3.30


The way to display Desktop icons in GNOME 3.28 onwards at the moment of writting this post and the whole issue with the removed handling of Desktop icons in Nautilus is explained well by Carlos Soriano a gnome shell extension developer in his blog post Desktop icons goes beta.

The good guy C. S. wrote  the his desktop icons gnome shell extension which is on github.com
To use it you have to fetch it and enable it by fetching the repo source code to gnome-shell extensions directory:
 

hipo@linux:~$ cd ~/.local/share/gnome-shell/extensions
hipo@linux:~$ git clone https://gitlab.gnome.org/World/ShellExtensions/desktop-icons
hipo@linux:~$ mkdir 'desktop-icons@csoriano'
hipo@linux:~$ mv desktop-icons/* 'desktop-icons@csoriano'/
hipo@linux:~$ rm -rf desktop-icons/


Now you should use the gnome-tweaks command tool to enable the new added gnome-shell extension.

hipo@linux:~$ gnome-tweaks


gnome-tweak-on-debian-testing-linux-screenshot

Once enabled your Desktop icons will appear as usual as seen in below shot, the downside this solutions is icons as seen in below screenshot is that pictures doesn't have Thumbnail pictures generated … and icons when kept on with mouse over can move only in a selected square like perimeter (when moved left / right / up down side). That "woody" icon movement sucks a bit but much better than no icons at all.

gnome-3.30-general-desktop-solved-missing-icons-desktop-screenshot-on-debian-linux

2. Displaying Missing Desktop icons in GNOME Flashback 3.30

I really love GNOME Flashback as it used to be a good replacement for Linux MATE (which is the fork of GNOME2 and not bad but lacks Metacity Window Manager and some of the Eye Candy that GNOME 3 and beside that even MATE had to be slightly hacked to make look more like Classical GNOME 2 – for more on that check my previous article Fixing Mate Adwaita Theme problems on Debian and Ubuntu). 

At the moment when I tried to run gnome-tweaks under a GNOME Flashback session I got the following error:

hipo@jericho:~/.local/share/gnome-shell/extensions$ gnome-tweaks 
WARNING : Shell not installed or running
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/gtweak/app.py", line 30, in do_activate
    self.win = Window(self, model)
  File "/usr/lib/python3/dist-packages/gtweak/tweakview.py", line 38, in __init__
    self._model.load_tweaks(self)
  File "/usr/lib/python3/dist-packages/gtweak/tweakmodel.py", line 104, in load_tweaks
    mods = __import__("gtweak.tweaks", globals(), locals(), tweak_files, 0)
  File "/usr/lib/python3/dist-packages/gtweak/tweaks/tweak_group_general.py", line 14, in <module>
    _shell_not_ubuntu = _shell.mode != 'ubuntu'
AttributeError: 'NoneType' object has no attribute 'mode'

In regular GNOME session gnome-tweaks works fine and with the help of an GNOME Shell Extension addon it is possible to add the Missing Desktop icons however the only working fix for GNOME FlashBack 3.30 is to substitute nautilus (the default GNOME file manager) with NEMO (which is The Official file manager for Cinnamon Desktop Environment).
Thanksfully this is done relatively easy and all I had to do is to use a little "hack", e.g. install nemo.

root@linux:~# apt-get install –yes -qq nemo

And add a new auto-launcher for gnome that launches nemo file manager instead of nautilus.

To add the auto-launcher in GNOME I had to add a file with following content:

[Desktop Entry]
Type=Application
Name=Nemo
Comment=Start Nemo desktop at log in
Exec=nemo-desktop
OnlyShowIn=GNOME;
AutostartCondition=GSettings org.nemo.desktop show-desktop-icons
X-GNOME-AutoRestart=true
NoDisplay=true

to ~/.config/autostart/

For those who don't know GNOME has this handy way to set an autostart programs by using the specific .desktop extension files that have to be placed under $HOME/.config/autostart (where $HOME = the logged in user home directory).

The one liner to do so is:

echo '[Desktop Entry]
Type=Application
Name=Nemo
Comment=Start Nemo desktop at log in
Exec=nemo-desktop
OnlyShowIn=GNOME;
AutostartCondition=GSettings org.nemo.desktop show-desktop-icons
X-GNOME-AutoRestart=true
NoDisplay=true' >> ~/.config/autostart/nemo.desktop

Then I had to restart my GNOME FlashBack session (e.g. Log Out and Login with a new session) and the icons appeared.

classic-gnome-flashback-debian-gnu-linux-hipos-desktop-screenshot

The downside of this dirty workaround is that desktop icons even though showing up couldn't be moved (rearranged) freely on any location of desktop (are pretty much static) and the even worser  fact about this hack is you can't actually copy paste easily copy files from your Desktop within another desktop folder … 
 I know that's shitty but at the moment there is no better solution and this is better than nothing at all.

P.S. I tried downgrading my Debian Testing to Stable Stretch Linux again with the idea to use the old GNOME 3.22 that the Stable Debian distro provides but, ended up with a lot of mess after experimenting to downgrade using /etc/apt/preferences file records and substitution in /etc/apt/sources.list to include the stable .deb repository and apt dselect and aptitude package management tools. Officially downgrades are not encouraged and supported by Debian, but I hoped I could relatively easily do it by manually fixing the broken dependencies after removing debian packages manually combined with short for bash loops like I did in the past, but it seems this time I broke the system worse, so I could hardly return it back to normal operation in upgrading packages with a lot of manual hacking with apt-get and few one liner scripts. Thus I abandoned as a fix the possiiblity to downgrade Testing Debian to stable, I even considered switching from GNOME desktop environment to something more light as OpenBoxCinnamon / XFCE and gave them one more try but the results weren't nice, I reconsidered again to go back to using the Good Old GNU Step Window Maker as a GNOME alternative which in my opinion is still a great GUI environment for security crackers / sysadmins /hackers (programmers) and eventually perhaps I will switch back to using it, because GNOME is becoming more and more bloated with the years and I can hardly stand it … I mean I did not expected GNOME to be developed in the shitty Mobile Interface  (Unity) way, I have been a loyal user to GNOME for so many years and have lived trhough  all its mess over the years, its painful to see how the good and efficient GNOME 2 went the bad broken road of changing completely concepts and interface in GNOME 3.x
 

3. Closure

GNOME Desktop icons has been with GNOME users already for about 15+ years so IMHO the missing ability to add them easily through gnome tweak tool or Gnome Control Center is a absurd stupidity and killed at least 5 times out of my time to solve and the solution is far from good … I understand that in future the GNOME developers want to make GNOME as modular as possible through GNOME Shell Extensions however if you're removing such an important functionality that's for ages in most mainstream operating systems such as M$ Windows / Mac OS is an insanity. Through my quick research online I found the Missing Desktop Icons is experienced by other people on other Linux distros besides Debian I saw complains by Ubuntu / Fedora and Arch Linux users in forums and mailing lists.
What puzzles me why the reaction of such a major complained are not seriously considered by GNOME developers, especially after all the problems with transition from GNOME 2 -> GNOME 3 which already pushed a lot of GNOME users to move from GNOME to KDE / MATE  (like in Linux Mint whose GUI is based on Linux Mint). Definitely such a general issues would drive further enthusiasts from GNU / Linux and makes a great harm to the Free Software software community.
Hopefully the missing desktop icons hell will be solved in upcoming GNOME releases.

Virtualbox Shared folder set up on Linux between Host and Guest OS – Set up Virtualbox shared folder to Copy files from PC Host to Guest

Wednesday, September 12th, 2018

mount-shares-between-host-OS-and-guest-virtual-machine-howto-virtualbox-vbox-logo

How to set-up Virtualbox shared folder to Copy files from PC Host  and Guest Virtualized OS?

Running VirtualBox Host is an easy thing to set-up across all Operating Systems.  Once you have it sooner or later you will need to copy files from the VM Host OS (that in my case is GNU / Linux) to the virtualized Guest operating system (again in my case that's again another Linux ISO running indide the Virtual Machine).

Below are steps to follow To use Virtualbox Shared Folder functionality to copy files between VBox and your Desktop / server Linux install.

1. Install Virtualbox Guest Additions CD Image ISO

I've explained how to add the Guest Additions CD image thoroughfully in my previous article Howto enable Copy / Paste Virtualbox betwen Linux guest and Host OS
Anyways I'll repeat myself below for sake of clarity:

To do so use Oracle VBox menus (on the booted virtualized OS VBox window):

Devices -> Insert Guest additions CD Image

Mount the ISO inside the Linux Virtual Machine:

root@debian:~# mount /media/cdrom1/
 

If the mount fails and there are no files inside the mount point it might be because the virtualbox-dkms and virtualbox-guest-dkms packages might be missing on the Host OS.

To install them (on Debian GNU / Linux) assuming that you're using virtualbox default distro packages /etc/apt/sources.list :
 

apt-get install –yes -qq virtualbox-dkms virtualbox-guest-dkms


and run:

root@debian:/media/cdrom1# cd /media/cdrom1; sh VBoxLinuxAdditions.run


2. Create directory for Shared Folder that will be used to access Host / OS files from the Guest Virtualized OS
 

root@debian:~# mkdir /mnt/shared_folder

3. Map from VBox program interface Shared folder settings and Mount /mnt/shared_folder location

virtualbox-virtual-machine-devices-shared-folders-shared-folder-settings-linux-screenshot

Devices -> Shared Folder -> Shared Folder settings -> Transient Folders (click blue folder add small button right)

From Transient Folders add whatever directory you want to be shared from your local notebook / PC to the VM.

virtualbox-devices-Shared-Folder-Add-Shared-Folder-add-share-linux-screenshotDepending on whether you would like to mount the shared folder only for reading files (choose Read Only) to make it a permanent shared folder (and not just for the one session of current running Virtual Machine until its killed use Make Permanent) or check Auto-Mount tick if you want the shared_folder mapping to be mounted on every VM boot.

Once the shared_folder directory location is set-up from GUI menu click OK and in order for the settings to take effect, you'll need to restart the VM Guest with Linux (use halt command from terminal) or Power Off the Machine via the VBox menus.

To mount use command like:

mount -t vboxsf name_of_folder_linked_from_vbox  /mnt/name_folder_guest_os/


mount-vboxsf-shared-folder-mnt-shared-linux-guest-screenshot

In my case I wanted to share home folder /home so the command I used is:

root@debian:~# mount -t vboxsf  shared_folder /mnt/shared_folder


If everything is fine your Host OS file content from /home will be visible (for read and write if you Mapped it so) 
under /mnt/shared_folder …

And as Turtles Ninja used to heavily say Cowabunga !!! 🙂
You have it mounted and ready for file share between Desktop -> Virtualized OS.

 

Bear in mind that above mount command has to run as root (superuser) to succeed.

You now could copy files from your Host OS (running the Virtual Machine) and the Guest OS (Virtualized OS) using /mnt/shared_folder mount point without problems.

The example is if you want to share files between VirtualBox installed Linux and the Guest (Desktop / server) OS, however at many cases mounting your Host OS directory for root users might be not very practical but, instead you might prefer to do the mount for specific non admin user, for example I prefer to do the shared folder mount with my pointed non-root username hipo.

Here is how to do above VM shared_folder mount for non-root user:

First you need to know the exact UID / GID (User ID / Group ID) of user, you can get that with id command:

hipo@linux:~$  id
uid=1000(hipo) gid=1000(hipo) groups=1000(hipo),24(cdrom),25(floppy),29(audio),30(dip),44(video),46(plugdev),108(netdev),114(bluetooth),115(lpadmin),119(scanner)

As you see UID / GID in my case are 1000 / 1000

hipo@linux:~$ sudo mount -t vboxsf -o rw,uid=1000,gid=1000 shared_folder /mnt/shared_folder

mount-virtual-box-shared_folder-with-non-administration-permissions-non-root-permissions-id-and-mount-command-screenshot-linux


4. Mounting configured shared_folder to automatically mount into the Guest OS Linux on every boot

a) Configuring shared_folder auto-mount using /etc/rc.local

If you need the shared_folder to automatically mount next-time you boot the virtual machine quickest way is to add the mount command to /etc/rc.local (on Debian 8 and Debian 9 and newer Ubuntu Linuxes rc.local is missing by default to enable it to work like it worked before read follow my previous article ).

b) Configuring auto-mount for shared_folder through /etc/fstab

The more professional way to auto-mount on emulated OS VM boot time,  you could add the vboxsf mount definitions to /etc/fstab with your favourite text-editor mcedit, nano, joe etc. … (for me that's vim).

Syntax of /etc/fstab is as follows:
 

<Device> <Mount Point> <Type> <Options> <Dump> <Pass>

root@linux:~# vim /etc/fstab

shared_folder /mnt/shared_folder                                vboxsf rw,uid=1000,gid=1000 0 0

Note that you will want to change 1000 / 1000, id / gid with the ones of the non-admin user you would like to add to mount it for.

A quick way to add it to /etc/fstab with a shell one-liner is with command
 

root@linux:~# echo 'shared_folder /mnt/shared_folder                                vboxsf rw,uid=1000,gid=1000 0  0' >> /etc/fstab

An alternative way to add a user to have permissions for vboxsf file system (without specifying the long -o uid=1000,gid=1000 options is to simply add the username in question to group vboxsf like so:

c) Adding non super user username to vboxsf group

root@linux:~# usermod -G vboxsf hipo
root@linux:~# grep -i vboxsf /etc/group
vboxsf:x:999:hipo

hipo@linux:~$ sudo mount -t vboxsf  shared_folder /mnt/shared_folder

without the extra arguments and the options to pass to /etc/fstab (for eventual requirement to auto mount the shared_folder) would be more simple e.g.:

echo 'shared_folder /mnt/shared_folder                                vboxsf ' >> /etc/fstab

One note to make here is if the uesr is added to vboxsf the line for /etc/fstab to auto mount to mount for root user and non-root will be identical.

Then you can get the /etc/fstab auto-mount configured tested by running:

c) Checking auto-mount is working

hipo@linux:~# mount -a
hipo@linux:~# mount |grep -i vboxsf
shared_folder on /mnt/shared_folder type vboxsf (rw,nodev,relatime)


5. What if you end up with mounting failed errors ? – What might be causing the mounting failed Protocol error (a few things to check to solve)


In case of troubles with the mount you might get an error like:

hipo@linux:~# mount -t vboxsf  share_folder /mnt/shared_folder

/sbin/mount.vboxsf: mounting failed with the error: Protocol error


This error might be caused because of Insert Guest Additions CD Image might be not properly enabled and installed using the ISO provided VBoxLinuxAdditions.sh shell script.
Other common reason you might get this error if you have mistyped the Folder name: given in Shared Folders -> Folder Path -> Add Share for example I have given shared_folder as a Map name but as you can see in above mount -t vboxsf, I've mistyped share_folder instead of the correct one shared_folder inserted.
In some VBox releases this error was caused by bugs in the Virtual Machine.
 

virtualbox-virtual-machine-shared-folder-transient-folder-add-folder-linux-VM-guest-linux

One useful tip is to be able to check whether a Virtualbox Virtual Machine has a configured shared_folder (if you're logging to manage the machine on remote server – nomatter whether you have logged in with VNC / Teamviewer / Citrix etc. or via SSH session.

To do so use VBoxControl as of time of writting usually located on most distributions under (/usr/bin/VBoxControl)
 

hipo@linux:~# VBoxControl sharedfolder list -automount
Oracle VM VirtualBox Guest Additions Command Line Management Interface Version 5.2.18
(C) 2008-2018 Oracle Corporation
All rights reserved.

Auto-mounted Shared Folder mappings (0):

No Shared Folders available.

You can use VBoxControl command to get set and list a number of settings on the VBox VM, here is an useful example with it where you get information about numerous VBox info values:

root@linux:~# VBoxControl guestproperty enumerate
Oracle VM VirtualBox Guest Additions Command Line Management Interface Version 5.2.18
(C) 2008-2018 Oracle Corporation
All rights reserved.

Name: /VirtualBox/GuestInfo/OS/Product, value: Linux, timestamp: 1536681633430852000, flags: <NULL>
Name: /VirtualBox/GuestInfo/Net/0/V4/IP, value: 10.0.2.15, timestamp: 1536681633438717000, flags: <NULL>
Name: /VirtualBox/HostInfo/GUI/LanguageID, value: en_US, timestamp: 1536697521395621000, flags: RDONLYGUEST
Name: /VirtualBox/GuestInfo/Net/0/MAC, value: 08002762FA1C, timestamp: 1536681633442120000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/ServicePack, value: <NULL>, timestamp: 1536681633431259000, flags: <NULL>
Name: /VirtualBox/HostInfo/VBoxVerExt, value: 5.2.18, timestamp: 1536681619002646000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/Net/0/V4/Netmask, value: 255.255.255.0, timestamp: 1536681633440157000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/Version, value: #1 SMP Debian 4.9.110-3+deb9u2 (2018-08-13), timestamp: 1536681633431125000, flags: <NULL>
Name: /VirtualBox/GuestAdd/VersionExt, value: 5.2.18, timestamp: 1536681633431582000, flags: <NULL>
Name: /VirtualBox/GuestAdd/Revision, value: 124319, timestamp: 1536681633432515000, flags: <NULL>
Name: /VirtualBox/HostGuest/SysprepExec, value: <NULL>, timestamp: 1536681619002355000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/OS/LoggedInUsers, value: 1, timestamp: 1536681673447293000, flags: TRANSIENT, TRANSRESET
Name: /VirtualBox/GuestInfo/Net/0/Status, value: Up, timestamp: 1536681633443911000, flags: <NULL>
Name: /VirtualBox/GuestInfo/Net/0/Name, value: enp0s3, timestamp: 1536681633445302000, flags: <NULL>
Name: /VirtualBox/HostGuest/SysprepArgs, value: <NULL>, timestamp: 1536681619002387000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestAdd/Version, value: 5.2.18, timestamp: 1536681633431419000, flags: <NULL>
Name: /VirtualBox/HostInfo/VBoxRev, value: 124319, timestamp: 1536681619002668000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/Net/0/V4/Broadcast, value: 10.0.2.255, timestamp: 1536681633439531000, flags: <NULL>
Name: /VirtualBox/HostInfo/VBoxVer, value: 5.2.18, timestamp: 1536681619002613000, flags: TRANSIENT, RDONLYGUEST
Name: /VirtualBox/GuestInfo/OS/LoggedInUsersList, value: hipo, timestamp: 1536681673446498000, flags: TRANSIENT, TRANSRESET
Name: /VirtualBox/GuestInfo/Net/Count, value: 1, timestamp: 1536698949773993000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/Release, value: 4.9.0-7-amd64, timestamp: 1536681633431001000, flags: <NULL>
Name: /VirtualBox/GuestInfo/OS/NoLoggedInUsers, value: false, timestamp: 1536681673447965000, flags: TRANSIENT, TRANSRESET
Name: /VirtualBox/GuestAdd/HostVerLastChecked, value: 5.2.18, timestamp: 1536681702832389000, flags: <NULL>

Hope you enjoyed ! Have phun! 🙂

Copy Paste Virtualbox enable between Linux Host and Guest Virtual Machine

Thursday, September 6th, 2018

enable-copy-paste-between-linux-host-and-guest-OS-virtual-machine-virtualbox-vbox-logo

Copy / Pasting has become a vital part of our digital lifes, not having it in our days is insane, most of our System Administration jobs / Programmer or Office (Secretary) stuff daily without Copy / Paste is a unthinkable.

Lately I have been playing with Virtual Machines as I need to test some Dev Ops related stuff I install Jenkins write and test scripts and tools inside a VM, for that to happen I needed a working VM and because I am a Free Software supporter my VM of choice is usually Virtualbox. Even though Virtualbox is not the best and most performance efficient Virtual Machine out there for a small tasks and home usage dev / testing it does a great job, I have faced a problem with Copy / Pasting not working in VBox between the VM -> Guest OS, that's why I decided to write this step by step guide to help people who face the same issue.

For people who are starting with Oracle VirtualBox and you just have Created a New Virtual Machine and installed GNU / Linux or FreeBSD one common set back problem you will experience is the the Copy / Paste functionality between the VM Host Machine and the Guest won't be working out of the box. That's pretty much annoying thing and since usually one installs different Virtual Machines with different Operating Systems as a test bed for Software installs on top of various versions of OSes the lack of Copy, Paste functionality which is not there by default makes copy / pasting programming code / commands etc. between your local Desktop notebook or remote  server Machine and the VBox Virtualized Guest mostly unusuable …

Besides that integration (sharing resources / improved VM performance) between the Host (which is for example your Desktop notebook or PC) and the Virtualized Operating system be it some kind of UNIX (FreeBSD) etc. is not optimal until you enable an extra integration between VirtualBox and your (Host OS – that in my case is Debian 9 GNU / Linux but it can be Microsoft Windows XX as well or any other *nix like OS).In order for this Integration between your Host OS and Guest OS and Copy / Paste features between the two to work you need to Enable Guest Additions CD image (Software) that is part of VirtualBox installation on the Host OS and once enabled to mount (Attach the Vbox provided Virtual CD) from within the Guest OS (that in my case is another Debian 9 Stretch Linux that is installed inside the VM) and run a script that will install the necessery VirtualBox software inside the Guest OS Linux.
 

This is done in 3 easy steps:

STEP 1: Enable Vbox (Guest Additions CD Image)


virtualbox-VM-enable-insert-guest-additions-CD-image-menu-screenshot-debian-linux

Devices -> Insert Guest Additions CD image


2. Enable Shared Clipboard and Drag and Drop from the Virtual Machine

virtualbox-VM-enable-devices-shared-slipboard-bidirectional-menu-screenshot-debian-linux
 

Devices -> Shared Clipboard -> Bidirectional

virtualbox-VM-enable-devices-drag-and-drop-bidirectional-menu-screenshot-debian-linux
 

Devices -> Drag and Drop -> Bidirectional


3. Install development packages that are required by VBoxLinuxAdditions.run script

a) First thing is to use Virtual Box program interface menu and enable Insert Guest Additions CD Image option (assuming that you have the Linux Guest OS running).

virtualbox-VM-enable-insert-guest-additions-CD-image-menu-screenshot-debian-linux
 

Devices -> Insert Guest Additions CD image


https://pc-freak.net/images/virtualbox-virtual-machine-guest-os-settings

You can do it also from main VirtualBox interface (without having a Virtual machine running) by clicking over the desired Guest OS or pressting CTRL + S key combination

b) Next step is to mount the Virtual CD Guest Additions inside the Guest OS VM

To mount the Virtual content provided by the just ticked VBOX "Insert Guest Additions CD" menu, inside the Guest OS Linux, you have to run simple mount command:

root@debian:~# mount /media/cdrom1
mount: /dev/sr1 is write-protected, mounting read-only

c) Install necessery packages that VBoxLinuxAdditions.run will use

Further on VBoxLinuxAdditions.run (additions script) that adds the integration between the Host operating system and the Guest OS depends on some essential tools necessery for building (compiling) / developing software on Linux, this are:

1.) build-essential – a meta package that will install the following set of packages:

dpkg-dev fakeroot g++ g++-6 libalgorithm-diff-perl libalgorithm-diff-xs-perl libalgorithm-merge-perl libdpkg-perl libfakeroot libfile-fcntllock-perl libstdc++-6-dev


which are necessery for creation .deb packages, compiling code and other various activitions. a) build-essential is a very important Debian based distro package and if you happen to be new to Linux or just starting learning how to develop programs on Linux, you will soon realize you will need it installed across almost all Linux OS hosts you maintain or develop on …

VirtualBox-VBoxLinuxAdditions-run-script-missing-headers-gcc-perl-how-to-fix

root@debian:~# apt-get install –yes build-essential linux-headers-$(uname -r) gcc perl make


2.) The linux-headers package in my case that it is is linux-headers-4.9.0-7-amd64 is important as it provides kernel header files that are necessery when compiling and integrating kernel modules VBoxLinuxAdditions.run script depends on it as it builds a kernel module that adds the integration (that enables Copy / Paste and performance inprovements) between the Host VM machine and Guest OS

3.) gcc perl packages this two provides the C compiler and perl scripting programming language interpreter which are also used by VBoxLinuxAdditions.run script.


Now run VBoxLinuxAdditions.run:

As you see in above screenshot the

root@debian:~#
root@debian:/media/cdrom1# sh VBoxLinuxAdditions.run
Verifying archive integrity… All good.
Uncompressing VirtualBox 5.2.18 Guest Additions for Linux……..
VirtualBox Guest Additions installer
Removing installed version 5.2.18 of VirtualBox Guest Additions…
Copying additional installer modules …
Installing additional modules …
VirtualBox Guest Additions: Building the VirtualBox Guest Additions kernel modules.  This may take a while.
VirtualBox Guest Additions: Running kernel modules will not be replaced until the system is restarted
VirtualBox Guest Additions: Starting.


If everything is fine you should get command output like above.

Above are the steps given to follow on current latest Debian Linux 9.5 (Stretch) as a Guest OS (this tutorial should be working also on Ubuntu / Mint and other deb package based distributions for RPM package based Linuxes Fedora / CentOS check out my previous toturial how to enable Linux Guest Virtualbox Addition on Redhat based distos.)

P. S.

What about Mac OS X since it is based on FreeBSD and it includes a lot of GNU licensing programs?

If you wonder whether on Mac OS X you don't need to run guest additions script such as (VBoxLinuxAdditions.run) on Mac Host -> Guest OS integration is done only by enabling the feature from VBox GUI interface via:
 

Devices -> Insert Guest Additions CD Image

What about enabling Copy / Paste on Linux Host VirtualBox hosting a Windows Guest OS?

Enabling Copy / Paste on a Windows Virtual Machine (I wrote about it earlier here), follows the same steps as in this tutorial.
The only difference is instead of running the VBoxLinuxAdditions.sh you have to navigate to the CD from Windows Explorer and run the appropriate .exe file depending on your architecture (X86 or 64 bit), the files to run on the virtual CDROM are one of the 3:

1. VBoxWindowsAdditions-amd64.exe
2. VBoxWindowsAdditions.exe
3. VBoxWindowsAdditions-x86.exe

virtualbox-vm-guest-additions-autoplay-web-on-windows-os

Follow the click through interface and you will have the Copy / Paste between your Linux -> Windows OS working.

Happy Copy / Pasting ! 🙂

Resize a VirtualBox guest Linux VDI Disk under Linux Host

Tuesday, September 4th, 2018


https://pc-freak.net/images/virtualbox-virtual-machine-guest-Windows-10-Linux-Debian-9-screenshot

I am using Oracle VirtualBox virtual machine to experiment with things before I deploy them on my servers. Recently I installed Debian 9 in a hurry (without much taking attention on the configuration options during VM machine creation) and the negative results of my lack of attention came quickly as my Linux Virtualbox guest OS just ran of space a little time after I have installed a Debian Stretch 9 OS into the virtual machine ..

I didn't realized immediately the "No free disk space" error was there because, after installing a few sets of Debian packages (Exim MTA – exim4-damon-heavy .. related etc.) immediately, shutdown the Virtual Machine running (even of this very moment) on my Thinkpad T420 notebook and went to bed.

This morning I switched on the PC booted my notebook and launched the VM to do another set of experiments inside it, however it seemed it failed to load all services printed in text on Linux boot and the GDM3 Greater never appearead on screen- for those who don't know GDM3 is Linux Graphical environment Authentication / Login program.

gdm3-debian-9-login-errors-low-disk-space-no-free-space-on-disk

I have tried a VirtualBox VM Restart,  hoping that the cause of my problems might be VMachine bug (as I'm running the latest stable version of VirtualBox (Virtualbox 5.2) taken from VBox Linux download page . On Next boot weirdly the OS booted until the GDM greater but inputting the password did not load into GNOME but kept repeatedly asking for password.

After another VM restart (shutdown + re-boot), I could eventually login but I got a Low disk space error like in below screenshot

pc-freak.net/images/debian-linux-9-running-inside-virtual-machine-low-disk-space-stroke-selection

So how to fix the Virtual Debian Install Low Disk Space?

As of today September 4 2018 the way to extend the hard disk, that was prepared originally for the Virtual Machine install you need to give a check inside your Linux home (~/) directory under Virtualbox VMs find the folder that is equivallent to the Virtual Machine (whose Hard Disk Drive) you would like to extend, do a ls command check to identify the exact name of the VDI – [Virtual Desktop Infrastructure] file (in my case, that's is Debian 9.vdi) and use VboxManage modifyhd options command like shown below to resize VM HDD to more gigabytes

1. Resize the Virtualbox VM .VDI file using command line

root@jericho:/home/hipo/VirtualBox VMs/Debian 9# VBoxManage modifyhd 'Debian 9.vdi' –resize 40000
0%…10%…20%…30%…40%…50%…60%…70%…80%…90%…100%

As you see I am resizing my Hard Drive for this Virtual Machine to 40000 = (40 Gigabytes), if you have need / more disk space you might want to set something like 100000 (100GB).

2. Resizing .VDI file (Virtual Machine) using VirtualBox GUI

Click on Global Tools button (located leftside upper side on the screen

virtualbox-resize-debian-linux-harddrive-global-tools-screenshot

Drag the bar Size: to the Hard Drive partition size you want it to be …
 

So far so good, now the image file is resized but the GNU / Linux partition is still being small, so we need to also do repartitioning, once booted into the VM in order to stretch the HDD size to 40 Gigas.

Next install and use gparted Linux tool to add the free space to your root partition, use the gparted

Inside the VM instal the tool with:
 

Inside virtualmachine's in gnome-terminal / xterm etc. depending on the graphical environment used do install with apt-get:

debian:# apt-get install –yes gparted

debian~:# gparted


Notice that gparted has to be ran as a root superuser.

Run GParted and create new EXT3 filesystem that is 10GB (the size of the new created partition).

If you have installed Debian to place all partitions under / (root directory /dev/sda1) then the fresh new partition to create should be
/dev/sda3, anyways just look closely in EXT3 and in your case if the partiition is named differently create according to proper partition /dev/ naming.

I'll not run into details on how to create the partition with GParted as the program interface is very self-explanatory, the only thing is to apply the update to create partition and the ext3 filesystem, that's being done
with a green tick:

Next step is to check with fdisk whether, we have ext3 properly created  filesystem as we've done already with GPARTED:

Once we have the partition created with EXT3 filesystem, we're ready to move /usr temporary to other folder, I use usually /root for the move but you can create anywhere a new folder for that and move to there.

To move to /root directory run again in terminal:

debian:~# mv /usr /root
debian:~# mkdir /usr

Note that during the move operations, your Desktop icons will become without (with broken) pictures and the default Debian background picture is to disappear, that's because the GUI environment will soon realize /usr/ libraries that're periodically reloaded in memory are missing and will be unable to reload them as it does in a cycle.

That should take a few minutes, so grab a coffee or if you're a smoker (hope not as smoking kills 🙂 ), in 5 / 10 minutes time depending on your computer / server configuration, it will be over, so we're ready to create new /usr dir and mount the  new partition:

debian:~# mount /dev/sda3 /usr

howto-extend-root-filesystem-disk-space-linux-move-usr-folder-to-root-temporary-debian-gnu-linux1

Now we check with mount command whether mount is fine:

check-if-filesystem-is-properly-mounted-linux-debian-screenshot


Now  /dev/sda3 is mounted under /usr  and we have to move back /root/usr directory content back to the newly mounted /usr so we run command:
 

debian:~#  mv /root/usr/* /usr/*


Finally we need to create proper records for the new partition inside /etc/fstab (fstab –FileSystem Tab file – the file which describes instructs the Linux OS what partition to boot where, what)

Nginx increase security by putting websites into Linux jails howto

Monday, August 27th, 2018

linux-jail-nginx-webserver-increase-security-by-putting-it-and-its-data-into-jail-environment

If you're sysadmining a large numbers of shared hosted websites which use Nginx Webserver to interpret PHP scripts and serve HTML, Javascript, CSS … whatever data.

You realize the high amount of risk that comes with a possible successful security breach / hack into a server by a malicious cracker. Compromising Nginx Webserver by an intruder automatically would mean that not only all users web data will get compromised, but the attacker would get an immediate access to other data such as Email or SQL (if the server is running multiple services).

Nowadays it is not so common thing to have a multiple shared websites on the same server together with other services, but historically there are many legacy servers / webservers left which host some 50 or 100+ websites.

Of course the best thing to do is to isolate each and every website into a separate Virtual Container however as this is a lot of work and small and mid-sized companies refuse to spend money on mostly anything this might be not an option for you.

Considering that this might be your case and you're running Nginx either as a Load Balancing, Reverse Proxy server etc. , even though Nginx is considered to be among the most secure webservers out there, there is absolutely no gurantee it would not get hacked and the server wouldn't get rooted by a script kiddie freak that just got in darknet some 0day exploit.

To minimize the impact of a possible Webserver hack it is a good idea to place all websites into Linux Jails.

linux-jail-simple-explained-diagram-chroot-jail

For those who hear about Linux Jail for a first time,
chroot() jail is a way to isolate a process / processes and its forked children from the rest of the *nix system. It should / could be used only for UNIX processes that aren't running as root (administrator user), because of the fact the superuser could break out (escape) the jail pretty easily.

Jailing processes is a concept that is pretty old that was first time introduced in UNIX version 7 back in the distant year 1979, and it was first implemented into BSD Operating System ver. 4.2 by Bill Joy (a notorious computer scientist and co-founder of Sun Microsystems). Its original use for the creation of so called HoneyPot – a computer security mechanism set to detect, deflect, or, in some manner, counteract attempts at unauthorized use of information systems that appears completely legimit service or part of website whose only goal is to track, isolate, and monitor intruders, a very similar to police string operations (baiting) of the suspect. It is pretty much like а bait set to collect the fish (which in this  case is the possible cracker).

linux-chroot-jail-environment-explained-jailing-hackers-and-intruders-unix

BSD Jails nowadays became very popular as iPhones environment where applications are deployed are inside a customly created chroot jail, the principle is exactly the same as in Linux.

But anyways enough talk, let's create a new jail and deploy set of system binaries for our Nginx installation, here is the things you will need:

1. You need to have set a directory where a copy of /bin/ls /bin/bash /bin/,  /bin/cat … /usr/bin binaries /lib and other base system Linux system binaries copy will reside.

server:~# mkdir -p /usr/local/chroot/nginx


2. You need to create the isolated environment backbone structure /etc/ , /dev, /var/, /usr/, /lib64/ (in case if deploying on 64 bit architecture Operating System).

server:~# export DIR_N=/usr/local/chroot/nginx;
server:~# mkdir -p $DIR_N/etc
server:~# mkdir -p $DIR_N/dev
server:~# mkdir -p $DIR_N/var
server:~# mkdir -p $DIR_N/usr
server:~# mkdir -p $DIR_N/usr/local/nginx
server:~# mkdir -p $DIR_N/tmp
server:~# chmod 1777 $DIR_N/tmp
server:~# mkdir -p $DIR_N/var/tmp
server:~# chmod 1777 $DIR_N/var/tmp
server:~# mkdir -p $DIR_N/lib64
server:~# mkdir -p $DIR_N/usr/local/

3. Create required device files for the new chroot environment

server:~# /bin/mknod -m 0666 $D/dev/null c 1 3
server:~# /bin/mknod -m 0666 $D/dev/random c 1 8
server:~# /bin/mknod -m 0444 $D/dev/urandom c 1 9

mknod COMMAND is used instead of the usual /bin/touch command to create block or character special files.

Once create the permissions of /usr/local/chroot/nginx/{dev/null, dev/random, dev/urandom} have to be look like so:

server:~# ls -l /usr/local/chroot/nginx/dev/{null,random,urandom}
crw-rw-rw- 1 root root 1, 3 Aug 17 09:13 /dev/null
crw-rw-rw- 1 root root 1, 8 Aug 17 09:13 /dev/random
crw-rw-rw- 1 root root 1, 9 Aug 17 09:13 /dev/urandom

4. Install nginx files into the chroot directory (copy all files of current nginx installation into the jail)
 

If your NGINX webserver installation was installed from source to keep it latest
and is installed in lets say, directory location /usr/local/nginx you have to copy /usr/local/nginx to /usr/local/chroot/nginx/usr/local/nginx, i.e:

server:~# /bin/cp -varf /usr/local/nginx/* /usr/local/chroot/nginx/usr/local/nginx


5. Copy necessery Linux system libraries to newly created jail
 

NGINX webserver is compiled to depend on various libraries from Linux system root e.g. /lib/* and /lib64/* therefore in order to the server work inside the chroot-ed environment you need to transfer this libraries to the jail folder /usr/local/chroot/nginx

If you are curious to find out which libraries exactly is nginx binary dependent on run:

server:~# ldd /usr/local/nginx/usr/local/nginx/sbin/nginx

        linux-vdso.so.1 (0x00007ffe3e952000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f2b4762c000)
        libcrypt.so.1 => /lib/x86_64-linux-gnu/libcrypt.so.1 (0x00007f2b473f4000)
        libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f2b47181000)
        libcrypto.so.0.9.8 => /usr/local/lib/libcrypto.so.0.9.8 (0x00007f2b46ddf000)
        libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f2b46bc5000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f2b46826000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f2b47849000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f2b46622000)


The best way is to copy only the libraries in the list from ldd command for best security, like so:

server: ~# cp -rpf /lib/x86_64-linux-gnu/libthread.so.0 /usr/local/chroot/nginx/lib/*
server: ~# cp -rpf library chroot_location

etc.

However if you're in a hurry (not a recommended practice) and you don't care for maximum security anyways (you don't worry the jail could be exploited from some of the many lib files not used by nginx and you don't  about HDD space), you can also copy whole /lib into the jail, like so:

server: ~# cp -rpf /lib/ /usr/local/chroot/nginx/usr/local/nginx/lib

NOTE! Once again copy whole /lib directory is a very bad practice but for a time pushing activities sometimes you can do it …


6. Copy /etc/ some base files and ld.so.conf.d , prelink.conf.d directories to jail environment
 

server:~# cp -rfv /etc/{group,prelink.cache,services,adjtime,shells,gshadow,shadow,hosts.deny,localtime,nsswitch.conf,nscd.conf,prelink.conf,protocols,hosts,passwd,ld.so.cache,ld.so.conf,resolv.conf,host.conf}  \
/usr/local/chroot/nginx/usr/local/nginx/etc

server:~# cp -avr /etc/{ld.so.conf.d,prelink.conf.d} /usr/local/chroot/nginx/nginx/etc


7. Copy HTML, CSS, Javascript websites data from the root directory to the chrooted nginx environment

server:~# nice -n 10 cp -rpf /usr/local/websites/ /usr/local/chroot/nginx/usr/local/


This could be really long if the websites are multiple gigabytes and million of files, but anyways the nice command should reduce a little bit the load on the server it is best practice to set some kind of temporary server maintenance page to show on the websites index in order to prevent the accessing server clients to not have interrupts (that's especially the case on older 7200 / 7400 RPM non-SSD HDDs.)
 

8. Stop old Nginx server outside of Chroot environment and start the new one inside the jail


a) Stop old nginx server

Either stop the old nginx using it start / stop / restart script inside /etc/init.d/nginx (if you have such installed) or directly kill the running webserver with:

server:~# killall -9 nginx

b) Test the chrooted nginx installation is correct and ready to run inside the chroot environment

server:~# /usr/sbin/chroot /usr/local/chroot/nginx /usr/local/nginx/nginx/sbin/nginx -t
server:~# /usr/sbin/chroot /usr/local/chroot/nginx /usr/local/nginx/nginx/sbin/nginx

c) Restart the chrooted nginx webserver – when necessery later

server:~# /usr/sbin/chroot /nginx /usr/local/chroot/nginx/sbin/nginx -s reload

d) Edit the chrooted nginx conf

If you need to edit nginx configuration, be aware that the chrooted NGINX will read its configuration from /usr/local/chroot/nginx/nginx/etc/conf/nginx.conf (i'm saying that if you by mistake forget and try to edit the old config that is usually under /usr/local/nginx/conf/nginx.conf

How to mount LVM partition volume on Linux

Wednesday, August 22nd, 2018

lvm-logical-volume-logical-volume-groups

(LVM) = Logical Volume Manager is a device mapper offering logical volume management for the Linux kernel. Virtually all modern GNU / Linux distributions has support for it and using LVM is used among almost all Hosting Providers on (dedicated) backend physical and Virtual XEN / VMWare etc. servers because it provides the ability to merge a number of disks into virtual volumes (for example you have a number of SSD Hard Drives on a server that are under a separate /dev/sda1 /dev/sda2 /dev/sdb3 /dev/sdb4 etc. and you want all the HDDs to appear as a single file system this is managed by Linux LVM.

Logical-volume-manager-linux-explained-diagram.svg

Picture sources Wikipedia

The use of LVM is somewhat similar to RAID 0 disk arrays, where the good about it it allows the removal and addition of hard disks in real time (broken hard disks) on servers to be replaced without service downtime as well as dynamic HDD volume resizal is possible. LVM allows also relatively easy encryption of multiple HDD volumes
with single password.

Discs can be organized in volume groups (so lets say 2 of the server Attached conventional Hard Disks, SCSI or SSDs can be attached to LVM1 and another 3 Hard Drives could be attached to LVM2 group etc.

LVM has been an integral part of Linux kernel since 1998.

lvm is available for install via apt, yum, dhf etc. under a package called lvm2, so to install it on Debian / Ubuntu Fedora Linux (if it is not already installed on the servers with).

– Install LVM2 On Debian / Ubuntu
 

debian:~# apt-get install –yes lvm2


– Install LVM2 on Fedora / CentOS (Redhat RPM based distros)

[root@centos ~]:# yum install -y lvm2


or

[root@fedora ~]:#  dhf install -y lvm2


I. Mounting LVM2 on Linux server after broken DISK change part of a LVM Volume

For example the HDD faileddue to bad sectors and physical HDD head damage damage  – the easiest way to figure that out if the server is running smartd or via a simple HDD test check from BIOS  ( as the ROOT partition is on a LVM it fails to boot properly. You have changed the broken HDD with a brand new and you need to remount the LVM either physically on the server console or remotely via some kind of BIOS KVM interface).

In my experience working for Santrex this was a common sysadmin job, as many of the Virtual Client servers as well as others irons situated in various DataCenters, were occasionally failing to boot and the monitoring system was reporting about the issues and we had to promptly react and bring the servers up.

Here is shortly how we managed to re-mount the LVM after the SSDs / HDDS were substituted:

    1.1. Execute fdisk, vgscan / lvdisplay command

fdisk-lvm-screenshot

lvdisplay-screenshot

vgscan scans all supported LVM block devices in the system for VGs (Virtual Groups)

vgscan-vgchange-screenshot-lvm

    1.2. Next issue vgchange command to activate volume
 

vgchange -ay


   
    1.3. Type lvs command to get information about logical volumes

lvs


   
    1.4. Create a mount point using the mkdir command

      That's because we wanted to check the LVM will get properly mounted on next server reboot).
   
     1.5. Mount an LVM volume using
 

server:~# mount /dev/mapper/DEVICE /path/to/mount_point

     1.6. To check the size of the LVM (mount points, mounted LVM /dev/names sizes and the amount of free space on each of them use)
 

server:~# df -T