Posts Tagged ‘freebsd’

Sysadmin tip: How to force a new Linux user account password change after logging to improve security

Thursday, June 18th, 2020

Reading Time: 4minutes

chage-linux-force-password-expiry-check-user-password-expiry-setting

Have you logged in through SSH to remote servers with the brand new given UNIX account in your company just to be prompted for your current Password immediately after logging and forced to change your password?
The smart sysadmins or security officers use this trick for many years to make sure the default set password for new user is set to a smarter user to prevent default password leaks which might later impose a severe security risk for a company Demiliterized networks confidential data etc.

If you haven't seen it yet and you're in the beautiful world of UNIX / Linux as a developer qa tester or sysadmin sooner or later you will face it.
Here of course I'm talking about plain password local account authentication using user / pass credentials stored in /etc/passwd or /etc/shadow.

Lets Say hello to the main command chage that is used to do this sysadmin trick.
chage command is used to change user password expiry information and  set and alter password aging parameters on user accounts.

 

1. Force chage to make password expire on next user login for a new created user
 

# chage -d 0 {user-name} 


Below is a real life example
 

chage-force-user-account-password-expiry-linux

 

2. Get information on when account expires

 

[hipo@linux ~]$ chage -l hipo
Last password change                                    : Apr 03, 2020
Password expires                                        : Jul 08, 2020
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 0
Maximum number of days between password change          : 90
Number of days of warning before password expires       : 14

 

3. Use chage to set user account password expiration

The most straight forward way to set an expiration date for an active user acct is with:

 

# chage -E 2020-08-16 username


To make the account get locked automatically if the password has expired and the user did not logged in to it for 2 days after its expiration.

# chage -I 2 username


– Set Password expire with Minimum days 7 (-n mindays 7), (-x maxdays 28) and (-w warndays 5)

# passwd -n 7 -x 28 -w 5 username

To check the passwod expiration settings use list command:

# chage -l username
Last password change                                    : юни 18, 2020
Password expires                                        : юли 16, 2020
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 7
Maximum number of days between password change          : 28
Number of days of warning before password expires       : 5

 

chage is a command is essential sysadmin command that is mentioned in every Learn Linux book out there, however due to its often rare used many people and sysadmins either, don't know it or learn of it only once it is needed. 
A note to make here is some sysadmins prefer to use usermod to set a password expire instead of chage.

usermod -e 2020-10-14 username

 

For those who wonder how to set password expiry on FreeBSD and other BSD-es is done, there it is done via the pw system user management tool as chage is not present there.

 

A note to make here is chage usually does not provide information for Linux user accounts that are stored in LDAP. To get information of such you can use ldapsearch with a query to the LDAP domain store with something like.
 

ldapsearch -x -ZZ -LLL -b dc=domain.com,dc=com objectClass=*


It is worthy to mention also another useful command when managing users this is getent used to get entries from Name Service Switch libraries. 
getent is useful to get various information from basic /etc/ stored db files such as /etc/services /etc/shadow, /etc/group, /etc/aliases, /etc/hosts and even do some simple rpc queries.

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

Sunday, October 14th, 2018

Reading Time: 22minutes

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-featuredVirtual 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 anSSH 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.

 

Optimize PNG images by compressing on GNU / Linux, FreeBSD server to Improve Website overall Performance

Monday, November 27th, 2017

Reading Time: 4minutes

how-to-optimize-your-png-pictures-to-reduce-size-and-save-speed-bandwidth-optipng-compression-tests-results

If you own a website with some few hundreds of .PNG images like 10 000 / 15 000 png images and the website shows to perform slow in Google PageSpeed Insights and is slow to open when Google Searched or Shared on Facebook / Twitter etc. then one recommended step to boost up the website opening speed is to compress (optimize) the .PNG pictures without loosing the images quality to both save space and account bandwidth you could use optipng even though this is not the only tool available to help you optimize and reduce the size of your images, some few other tools you might like to check out if you have more time are:

 a.)  pngcrush – optimizes PNG (Portable Network Graphics) files.
 b.)  pngnq – tool for optimizing PNG (Portable Network Graphics) images. It is a tool for quantizing PNG images in RGBA format.
 c.)  pngquant – PNG (Portable Network Graphics) image optimising utility. It is a command-line utility for converting 24/32-bit PNG images to paletted (8-bit) PNGs.
 

1. Install and Compress / optimize PNG / GIF / PNM / TIFF file format with optipng
 

OPTIPING tool recompresses the .PNG images to a smaller size without loosing any quality information, besides PNG file format it also supports (BMP, GIF, PNM and TIFF) image format.

If you don't have optipng installed on your server you can;

a.) install it on Redhat RPM based Linux distributions lets say CentOS Linux use:

 

[root@centos: ~]# yum install epel-release
[root@centos: ~]# yum install optipng

Note that, You will need to  first enable epel repo on centos 7

 

b.) If instead you're on a Debian GNU / Linux

debian:~# apt-get install optipng


c.) FreeBSD users can install it from FreeBSD ports with:

 

freebsd# cd /usr/ports/graphics/optipng
freebsd# make install clean

optipng syntax is quite self explanatory
optipng [options] what-ever-file.png


You can get a full list of possible command options with -? command, here is a list:

 

debian:~# optipng -?
Synopsis:
    optipng [options] files …
Files:
    Image files of type: PNG, BMP, GIF, PNM or TIFF
Basic options:
    -?, -h, -help    show this help
    -o <level>        optimization level (0-7)        [default: 2]
    -v            run in verbose mode / show copyright and version info
General options:
    -backup, -keep    keep a backup of the modified files
    -clobber        overwrite existing files
    -fix        enable error recovery
    -force        enforce writing of a new output file
    -preserve        preserve file attributes if possible
    -quiet, -silent    run in quiet mode
    -simulate        run in simulation mode
    -out <file>        write output file to <file>
    -dir <directory>    write output file(s) to <directory>
    -log <file>        log messages to <file>
    —            stop option switch parsing
Optimization options:
    -f <filters>    PNG delta filters (0-5)            [default: 0,5]
    -i <type>        PNG interlace type (0-1)
    -zc <levels>    zlib compression levels (1-9)        [default: 9]
    -zm <levels>    zlib memory levels (1-9)        [default: 8]
    -zs <strategies>    zlib compression strategies (0-3)    [default: 0-3]
    -zw <size>        zlib window size (256,512,1k,2k,4k,8k,16k,32k)
    -full        produce a full report on IDAT (might reduce speed)
    -nb            no bit depth reduction
    -nc            no color type reduction
    -np            no palette reduction
    -nx            no reductions
    -nz            no IDAT recoding
Editing options:
    -snip        cut one image out of multi-image or animation files
    -strip <objects>    strip metadata objects (e.g. "all")
Optimization levels:
    -o0        <=>    -o1 -nx -nz                (0 or 1 trials)
    -o1        <=>    -zc9 -zm8 -zs0 -f0            (1 trial)
            (or…)    -zc9 -zm8 -zs1 -f5            (1 trial)
    -o2        <=>    -zc9 -zm8 -zs0-3 -f0,5            (8 trials)
    -o3        <=>    -zc9 -zm8-9 -zs0-3 -f0,5        (16 trials)
    -o4        <=>    -zc9 -zm8 -zs0-3 -f0-5            (24 trials)
    -o5        <=>    -zc9 -zm8-9 -zs0-3 -f0-5        (48 trials)
    -o6        <=>    -zc1-9 -zm8 -zs0-3 -f0-5        (120 trials)
    -o7        <=>    -zc1-9 -zm8-9 -zs0-3 -f0-5        (240 trials)
    -o7 -zm1-9    <=>    -zc1-9 -zm1-9 -zs0-3 -f0-5        (1080 trials)
Notes:
    The combination for -o1 is chosen heuristically.
    Exhaustive combinations such as "-o7 -zm1-9" are not generally recommended.
Examples:
    optipng file.png                        (default speed)
    optipng -o5 file.png                    (slow)
    optipng -o7 file.png                    (very slow)

Just running it with, lets say -o7 arguments is enough for optipng to compress your image and reduce some 15 to 30% of picture size

optipng-o7 what-ever-image-you-have.png

optipng-example-on-reducing-image-screenshot-24.9-png-image-compression

2. Compress images without loosing quality recursively inside directory and subdirectories with optiping

a.) To optimize all pictures inside a single directory (without sub-directories) on remote server you can run, below command:
 

cd whatever-dir/
for i in *.png; do optipng -o6 -quiet -keep -preserve -dir optimized -log optipng-compress.log "$i"; done


As you can see a log is being written on what the command has done and the originals of the optimized images is going to be preserved, the optimize level is 6 is the PNG encoding level.

 

cd /var/www/your-site/images/
find . -type f -iname "*.png" -print0 | xargs -I {} -0 optipng -o6 -keep -preserve -log optipng-compress.log "{}"


This command is pretty handy to run on own dedicated server, if you don't have one just do it on your Linux computer at home or if you don't own a PC with Linux install any Deb / RPM based Linux inside VirtualBox or VMWare Virtual Machine and do it there, then upload to your Hosting Provider/ AmazonEC2 etc and Enjoy the increased website performance 🙂

 

How to make for loop (cycles) in KSH useful for FreeBSD / UNIX system administrators

Friday, November 3rd, 2017

Reading Time: 2minutes

korn-shell-how-to-make-loops-easily-for-sys-admin-purposes

Sometimes we have to administrate this operating systems such as FreeBSD / AIX / HP UX or even Mac OS server where by default due to historical reasons or for security bash shell is not avialable. That's not a common scenario but it happens so if as sysadmin we need to create for loops on ksh it is useful to know how to do that, as for loop cycles are one of the most important command line tools the sysadmin swiss army knife kind of.

So how to create a for loop (cycle) in ksh (Korn Shell)?

The most basic example for a KSH loop shell is below:
 

#!/bin/ksh
for i in 1 2 3 4 5
do
  echo "Welcome $i times"
done

 


Add the content to any file lets say ksh_loop.ksh then make it executable as you do in bash shells

 

 

$ chmod +x ksh_loop.ksh
$ ksh ksh_loop.ksh

 


The overall syntax of the for loop ksh command is as follows:

 

 

for {Variable} in {lists}
do
    echo ${Variable}
done

 


Hence to list lets say 20 iterations in a loop in ksh you can use something like:
 

#!/bin/ksh
for i in {1..20}
do
  echo "Just a simple echo Command $i times";
# add whatever system commands you like here
done

 


Example for some useful example with KSH loop is to list a directory content so you can execute whatever command you need on each of the files or directories inside

 

#!/bin/ksh
for f in $(ls /tmp/*)
do
        print "Iterating whatever command you like on /tmp dir : $f"
done


Other useful for loop iteration would be to print a file content line by line just like it is done in bash shell, you can do that with a small loop like belows:

 

#!/bin/ksh
for iteration_variable in $(cat  file_with-your-loved-content-to-iterate.txt)
do
        print "Current iteration like is : $iteration_variable"
done

 

FreeBSD post install configuration steps to make on fresh FreeBSD install to make ready for server and Desktop use

Saturday, October 28th, 2017

Reading Time: 3minutes

freebsd-post-install-configuration-steps-to-make-on-fresh-install-to-make-ready-for-server-freebsd-logo


1. Update binary packages

First thing to do just like on any new operating system install is to update / patch the server
 

# freebsd-update fetch
# freebsd-update install

 


2. Update FreeBSD port packages

As a FreeBSD administrator you will need ports every now and then so make sure you have them at their latest release for your FBSD release

 

# pkg update
# pkg upgrade

 


3. Install editors and bash

 

# pkg install nano vim joe bash bash_completion

 


4. Install sudo

To be able to run commands without becoming superuser root just like on any Linux you will probably want to have sudo package installed

# pkg install sudo

 

Sudo config file is under /usr/local/etc/sudoers

To edit it with syntax check enabled use visudo

 

# visudo

# sudo pkg update
 

 

If you want a regular account to have root superuser edit / modify and do things permissions

 

# pw groupmod wheel -M your_user_name

 

Then to make the wheel permissions work add to sudoers:

 

%wheel    ALL=(ALL=ALL)    ALL

5. FreeBSD modify personal information for account

 

# chpass your_user_name

To change your account and others to use bash instead of default freebsd csh

 

# csh -s /bin/bash your_user_name

 


7. Set a Static IP address for a FreeBSD server and configure DNS

Edit /etc/rc.local to look something like so

 

#ifconfig_em0="DHCP"
ifconfig_em0="inet 192.168.1.100 netmask 255.255.255.0"
# default gateway
defaultrouter="192.168.1.1"

 

/etc/rc.conf is also the file where you can easily enable / disable freebsd startup scripts

To restart network interafaces just like Debian Linux's /etc/init.d/networking restart type

 

# service netif restart
# service routing restart

 

To set Google DNS in FreeBSD just like in Linux add the IPs with nameserver prefix to /etc/resolv.conf

 

# echo 'nameserver 8.8.8.8' >> /etc/resolv.conf
# echo 'nameserver 8.8.8.8' >> /etc/resolv.conf
# echo 'search your-domain-name' >> /etc/resolv.conf

 

– If you need to change the hostname of the FreeBSD server change in /etc/rc.conf

hostname="your-freebsdhostname"

– To add multiple IP addresses to a network interface on FBSD add line like below to /etc/rc.conf

ifconfig_em0_alias0="192.168.1.5 netmask 255.255.255.255"
ifconfig_em0_alias1="192.168.1.6 netmask 255.255.255.255"

To apply changes and bring up the newly set multiple IPs

# service netif restart


8. Setting up proper timezone

If for some reason the Time zone is improperly set during FreeBSD install, you can later set that with

# tzsetup

9. Set up ntp time server synchronization daemon

# vim /etc/rc.conf

ntpd_enable="YES"
ntpd_sync_on_start="YES"

First command will bring up NTP server at start up and second make it synchroniza with Internet NTP servers, to restart ntp so it set proper time
immediately

# service ntpd start


10. Add additional SWAP space to FreeBSD server after install

– First we need to create the swap file with command and then set up proper permissions for it

# truncate -S 3G /swapf
# chmod 0600 /swapf

– Then to make the swapf being used on boot we need to add it to /etc/fstab

# echo "md99 none swap sw,file=/swapf,late 0 0" >> /etc/fstab

To immediately apply the new added swap to be used by the system run:

# swapon -aqL

To check various things on how swap is configured use

# swapinfo -g


11. Configure Firewall in FreeBSD

# vim /etc/rc.conf

firewall_enable="YES"
firewall_script="/usr/local/etc/ipfw.rules"

A very basic firewall to add to ipfw.rules file would be something like so:
 

    $IPF 70 allow all from any to any out keep-state
    $IPF 80 allow icmp from any to any
    # open port ftp

    $IPF 110 allow tcp from any to any 21 in
    $IPF 120 allow tcp from any to any 21 out

    # 22 for ssh
    $IPF 130 allow tcp from any to any 22 in
    $IPF 140 allow tcp from any to any 22 out

    # mail port 25

    $IPF 150 allow tcp from any to any 25 in
    $IPF 160 allow tcp from any to any 25 out

    # dns (53) udp and tcp in
    $IPF 170 allow udp from any to any 53 in
    $IPF 175 allow tcp from any to any 53 in

    # dns (53) udp and tcp out
    $IPF 180 allow udp from any to any 53 out
    $IPF 185 allow tcp from any to any 53 out

    # http (80),
    $IPF 200 allow tcp from any to any 80 in
    $IPF 210 allow tcp from any to any 80 out
    # deny and log everything
    $IPF 500 deny log all from any to any

To launch the firewall
 

# service ipfw start


To list current FreeBSD Firewall rules use

# ipfw list

Finally if you need to check your connections to the server just like Linux's netstat you might consider using sockstat comand
 

# sockstat -4 -6

– 4 -6 will list you network connections for ipv4 and ipv6 both tcp and udp

How to find and Delete Duplicate files in directory on Linux server with find and fdupes command

Monday, March 16th, 2015

Reading Time: 3minutes

search-duplcate-files-linux-command-and-graphical-tools-how-to-find-duplicate-files-on-linux-mac-and-windows-os

Linux / UNIX find command is very helpful to do a lot of tasks to us admins such as Deleting empty directories to free up occupied inodes or finding and printing only empty files within a root file system within all sub-directories
There is too much of uses of find, however one that is probably rarely used known by sysadmins find command use is how to search for duplicate files on a Linux server:
 

find -not -empty -type f -printf “%s\n” | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 –all-repeated=separate

If you're curious how does duplicate files finding works, they are found by comparing file sizes and MD5 signatures, followed by a byte-by-byte comparison.

Most common application of below command is when you want to search and get rid of someold obsolete files which you forgot to delete such as old /etc/ configurations, old SQL backups and PHP / Java / Python programming code files etc.

If you have to do a regular duplicate file find on multiple servers Linux servers perhaps you should install and use  fdupes command.
On Debian Linux to install it:

root@pcfreak:/# apt-cache show fdupes|grep -i descr -A 4
Description: identifies duplicate files within given directories
 FDupes uses md5sums and then a byte by byte comparison to find
 duplicate files within a set of directories. It has several useful
 options including recursion.
Homepage: http://code.google.com/p/fdupes/

 

root@pc-freak.net:/# apt-get install –yes fdupes

To search for duplicate files with fdupes in lets /etc/ just run fdupes without arguments:

 

root@pcfreak:/# fdupes /etc/
/etc/magic
/etc/magic.mime

/etc/odbc.ini
/etc/.pwd.lock
/etc/environment
/etc/odbcinst.ini

/etc/shadow-
/etc/shadow


If you want to look up for all duplicate files within root directory:
 

root@pcfreak:/# fdupes -r /etc/
Building file list /

 

You can also find duplicate files for multiple directories by just passing all directories as arguments to fdupes

 

root@pcfreak:/# fdupes -r /etc/ /usr/ /root /disk /nfs_mount /nas


The -r argument (makes a recursive subdirectory search for duplicates), if you want to also see what is the size of duplicate files found add -S option

 

fdupes -r -S /etc/ /usr/ /root /disk /nfs_mount /nas

 


If you want to delete all duplicate files within lets say /etc/

 

root@pcfreak:/# fdupes -d /etc/

fdupes is also available and installable also on RPM based Linux distros Fedora / RHEL / CentOS etc., install on CentOS with:
 

[root@centos~ ]# yum -y install fdupes


There is also a port available for those who want to run it on FreeBSD on BSD install it from ports:

 

freebsd# cd /usr/ports/sysutils/fdupes
freebsd# make install clean


If you have a GUI environment installed on the server and you don't want to bother with command line to search for all duplicate files under main filesystem and other lint (junk) files take a look at FSlint

FSlint-2.02-search-for-duplicate-and-lint-files-linux-gui-tool

If you're looking for a GUI cross platform duplicate file finder tool that runs on all major used Operating Systems Mac OS X / Windows / Linux take a look at dupeGuru

 

Fix “Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.” in FreeBSD

Monday, May 21st, 2012

Reading Time: 2minutes

bsdinstall-newboot-loader-menu-pv_entries_consider_increasing_vm_pmap_shpgrepproc

I'm running FreeBSD with Apache and PHP on it and I got in dmesg (kernel log), following error:

freebsd# dmesg|grep -i vm.pmap.shpgperproc
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.

The exact FreeBSD, Apache and php versions I have installed are:
 

freebsd# uname -a ; httpd -V ; php –version
FreeBSD pcfreak 7.2-RELEASE-p4 FreeBSD 7.2-RELEASE-p4 #0: Fri Oct 2 12:21:39 UTC 2009 root@i386-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC i386
Server version: Apache/2.0.64
Server built: Mar 13 2011 23:36:25Server's Module Magic Number: 20050127:14
Server loaded: APR 0.9.19, APR-UTIL 0.9.19
Compiled using: APR 0.9.19, APR-UTIL 0.9.19
Architecture: 32-bit
Server compiled with….
-D APACHE_MPM_DIR="server/mpm/prefork"
-D APR_HAS_SENDFILE
-D APR_HAS_MMAP
-D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
-D APR_USE_FLOCK_SERIALIZE
-D APR_USE_PTHREAD_SERIALIZE
-D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
-D APR_HAS_OTHER_CHILD
-D AP_HAVE_RELIABLE_PIPED_LOGS
-D HTTPD_ROOT="/usr/local"
-D SUEXEC_BIN="/usr/local/bin/suexec"
-D DEFAULT_PIDLOG="/var/run/httpd.pid"
-D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
-D DEFAULT_LOCKFILE="/var/run/accept.lock"
-D DEFAULT_ERRORLOG="logs/error_log"
-D AP_TYPES_CONFIG_FILE="etc/apache2/mime.types"
-D SERVER_CONFIG_FILE="etc/apache2/httpd.conf"
PHP 5.3.5 with Suhosin-Patch (cli) (built: Mar 14 2011 00:29:17)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
with eAccelerator v0.9.6.1, Copyright (c) 2004-2010 eAccelerator, by eAccelerator

After a bunch of research a FreeBSD forums thread , I've found the fix suggested by a guy.

The solution suggested in the forum is to raise up vm.pmap.pv_entry_ma to vm.pmap.pv_entry_max=1743504, however I've noticed this value is read only and cannot be changed on the BSD running kernel;

freebsd# sysctl vm.pmap.pv_entry_max=1743504
sysctl: oid 'vm.pmap.pv_entry_max' is read only

Instead to solve the;

Approaching the limit on PV entries, consider increasing either the vm.pmap.shpgperproc or the vm.pmap.pv_entry_max tunable.
, I had to add in /boot/loader.conf

vm.pmap.pde.mappings=68
vm.pmap.shpgperproc=500
vm.pmap.pv_entry_max=1743504

Adding this values through /boot/loader.conf set them on kernel boot time. I've seen also in the threads the consider increasing either the vm.pmap.shpgperproc is also encountered on FreeBSD hosts running Squid, Dansguardion and other web proxy softwares on busy hosts.

This problems are not likely to happen for people who are running latest FreeBSD releases (>8.3, 9.x), I've read in same above post in newer BSD kernels the vm.pmap is no longer existing in newer kernels.

‘host-name’ is blocked because of many connection errors; unblock with ‘mysqladmin flush-hosts’

Sunday, May 20th, 2012

Reading Time: 3minutes

mysql-logo-host-name-blocked-because-of-many-connection-errors
My home run machine MySQL server was suddenly down as I tried to check my blog and other sites today, the error I saw while trying to open, this blog as well as other hosted sites using the MySQL was:

Error establishing a database connection

The topology, where this error occured is simple, I have two hosts:

1. Apache version 2.0.64 compiled support externally PHP scripts interpretation via libphp – the host runs on (FreeBSD)

2. A Debian GNU / Linux squeeze running MySQL server version 5.1.61

The Apache host is assigned a local IP address 192.168.0.1 and the SQL server is running on a host with IP 192.168.0.2

To diagnose the error I've logged in to 192.168.0.2 and weirdly the mysql-server was appearing to run just fine:
 

debian:~# ps ax |grep -i mysql
31781 pts/0 S 0:00 /bin/sh /usr/bin/mysqld_safe
31940 pts/0 Sl 12:08 /usr/sbin/mysqld –basedir=/usr –datadir=/var/lib/mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –socket=/var/run/mysqld/mysqld.sock –port=3306
31941 pts/0 S 0:00 logger -t mysqld -p daemon.error
32292 pts/0 S+ 0:00 grep -i mysql

Moreover I could connect to the localhost SQL server with mysql -u root -p and it seemed to run fine. The error Error establishing a database connection meant that either something is messed up with the database or 192.168.0.2 Mysql port 3306 is not properly accessible.

My first guess was something is wrong due to some firewall rules, so I tried to connect from 192.168.0.1 to 192.168.0.2 with telnet:
 

freebsd# telnet 192.168.0.2 3306
Trying 192.168.0.2…
Connected to jericho.
Escape character is '^]'.
Host 'webserver' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'
Connection closed by foreign host.

Right after the telnet was initiated as I show in the above output the connection was immediately closed with the error:

Host 'webserver' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'Connection closed by foreign host.

In the error 'webserver' is my Apache machine set hostname. The error clearly states the problems with the 'webserver' apache host unable to connect to the SQL database are due to 'many connection errors' and a fix i suggested with mysqladmin flush-hosts

To temporary solve the error and restore my normal connectivity between the Apache and the SQL servers I logged I had to issue on the SQL host:

mysqladmin -u root -p flush-hostsEnter password:

Thogh this temporar fix restored accessibility to the databases and hence the websites errors were resolved, this doesn't guarantee that in the future I wouldn't end up in the same situation and therefore I looked for a permanent fix to the issues once and for all.

The permanent fix consists in changing the default value set for max_connect_error in /etc/mysql/my.cnf, which by default is not too high. Therefore to raise up the variable value, added in my.cnf in conf section [mysqld]:

debian:~# vim /etc/mysql/my.cnf
...
max_connect_errors=4294967295

and afterwards restarted MYSQL:

debian:~# /etc/init.d/mysql restart
Stopping MySQL database server: mysqld.
Starting MySQL database server: mysqld.
Checking for corrupt, not cleanly closed and upgrade needing tables..

To make sure the assigned max_connect_errors=4294967295 is never reached due to Apache to SQL connection errors, I've also added as a cronjob.

debian:~# crontab -u root -e
00 03 * * * mysqladmin flush-hosts

In the cron I have omitted the mysqladmin -u root -p (user/pass) input options because for convenience I have already stored the mysql root password in /root/.my.cnf

Here is how /root/.my.cnf looks like:

debian:~# cat /root/.my.cnf
[client]
user=root
password=a_secret_sql_password

Now hopefully, this would permanently solve SQL's 'failure to accept connections' due to too many connection errors for future.