Posts Tagged ‘page’

A list of Christian Metal website resources on the Net for Christian Metal lovers

Thursday, July 26th, 2012

I’ve been an old times Metal head. The moment I accepted Jesus Christ as a Lord and Saviour and been visited by the Lord’s Holy Ghost grace, my life changed severely. I found out most of the metal bands, I used to be regularly listening to is against Christ and anti-christian in essence, I still however hold my love for Metal as my teenage years were dominated by Metal Music. Happily I found there is plenty of nice Metal music a Metal head could enjoy that are written for glorification of Christ and hence did not have the negative spiritual anti-christian charge that is so typical for a lot of the bads in the metal music world. Recently I’m not listening to as much music as few years from now but still every now and then I like playing some of my old Christian metal loved bands. I was maintaining a small list of Christian metal nice bands I found and playlisted on youtube. If you’re a metal geek you might enjoy my old christian metal playlist here :) .

For Christians, who are looking for online Christian Metal community I also suggest you check out Firestream – The believer’s Heavy Music Refugee . There are plenty of other interesting places on the net dedicated for Christian metal fans;;;

I will end up this post with 2 videos of one very favourite Ukrainian Christian Metal band – Angel 7;

Angel 7 – Jesus the Saviour

Angel 7 – The Last Day

There are probably plenty of other nice Christian Metal sites and resources on the net; surely I’m missing a lot here? if you know some other good Christian Rock / Metal resources please drop a comment.

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How to fix bug with WordPress domain extra trailing slash (Double wordpress trailing slash)

Monday, July 9th, 2012

How to fix bug with wordpress extra slash, domain double slash issue pic

2 of the wordpress installations, I take care for had been reported an annoying bug today by some colleagues.
The bug consisted in double trailing slash at the end of the domain url e.g.;

http://our-company-domainname.com//

As a result in the urls everywhere there was the double trailing slash appearing i.e.::

http://our-company-domainname.com//countact-us/
http://our-company-domainname.com//languages/

etc.

The bug was reported to happen in the multiolingual version of the wordpress based sites, as the Qtranslate plugin is used on this installations to achieve multiple languages it seemed at first logical that the double slash domain and url wordpress issues are caused for some reason by qTranslate.

Therefore, I initially looked for the cause of the problem, within the wordpress admin settings for qTranslate plugin. After not finding any clue pointing the bug to be related to qTranslate, I've then checked the settings for each individual wordpress Page and Post (There in posts usually one can manually set the exact url pointing to each post and page).
The double slash appeared also in each Post and Page and it wasn't possible to edit the complete URL address to remove the double trailin slashes. My next assumption was the cause for the double slash appearing on each site link is because of something wrong with the sites .htaccess, therefore I checked in the wp main sites directory .htaccess
Strangely .htacces seemed OKAY and there was any rule that somehow might lead to double slashes in URL. WP-sites .htaccess looked like so:
 

server:/home/wp-site1/www# cat .htaccess
RewriteEngine On
RewriteBase /

# Rewrite rules for new content and scripts folder
RewriteRule ^jscripts/(.*)$ wp-includes/js/$1
RewriteRule ^gallery/(.*)$ wp-content/uploads/$1
RewriteRule ^modules/(.*)$ wp-content/plugins/$1
RewriteRule ^gui/(.*)/(.*)$ wp-content/themes/$1/$2 [L]

# Disable direct acceees to wp files if referer is not valid
#RewriteCond %{THE_REQUEST} .wp-*
#RewriteCond %{REQUEST_URI} .wp-*
#RewriteCond %{REQUEST_URI} !.*media-upload.php.*
#RewriteCond %{HTTP_REFERER} !.*cadia.*
#RewriteRule . /error404 [L]

# Standard WordPress rewrite
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

Onwards, I thought a possible way to fix bug by adding mod_rewrite rules in .htaccess which would do a redirect all requests to http://www.our-company-domainname.com//contact-us/ to http://www.our-company-domainname.com//contact-us/ etc. like so:

RewriteRule ^/(.*)$ /$1

This for unknown reasons to me didn't worked either, finally thanks God I remembered to check the variables in wp-config.php (some month ago or so I added there some variables in order to improve the wordpress websites opening times).

I've figured out I did a mistake in one of the variables by adding an ending slash to the URL. The variable added was:

define('WP_HOME','http://our-company-domainname.com/');

whether instead it should be without the ending trailing slash like so:

define('WP_HOME','http://our-company-domainname.com');

By removing the ending trailing slash:

define('WP_HOME','http://our-company-domainname.com/');

to:

define('WP_HOME','http://our-company-domainname.com');
fixed the issue.
Cheers ;)

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HasciiCAM supposed to stream ASCII video over the network on GNU / Linux

Tuesday, May 22nd, 2012

Richard M. Stallman (RMS) Face portrait rendered in ASCII art from a video with hasciicam
To continue with my lately ASCII centered articles I found hasciicam
hasciicam is a program to stream ASCII video over the network on Linux and probably can be easily made working on FreeBSDtoo.

The project concept is interesting in a matter of fun (play) point of view, however not too usable as we all know ASCII character looking faces doesn't look too pretty.

Below is the Debian (Squeeze) package description:

noah:~# apt-cache show hasciicam|grep -i description -A 7
Description: (h)ascii for the masses: live video as text
Hasciicam makes it possible to have live ASCII video on the web. It
captures video from a tv card and renders it into ascii, formatting the
output into an html page with a refresh tag or in a live ASCII window or
in a simple text file as well, giving the possibility to anybody that has a
bttv card, a Linux box and a cheap modem line to show a live ASCII video
feed that can be browsable without any need for plugin, java etc.
Homepage: http://ascii.dyne.org/

On hasciicam Project webpage is it is stated as a hardware you need to have:
 

"As hardware you need to have a webcam or a videocard supported by "video 4 linux", most of the gear you can buy around should work well."

To install and test it I run:

noah:~# apt-get --yes install hasciicam

Though it is stated on the project website supposed to work display video fine with most 'linux ready' webcams, it didn't with this very standard one.

Here is the exact WebCamera model as identified to the kernel:

noah:~# dmesg|grep -i camera
[ 1.433661] usb 2-2: Product: USB2.0 Camera
[ 10.107840] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1e4e:0102)
[ 10.110660] input: USB2.0 Camera as /devices/pci0000:00/0000:00:1d.7/usb2/2-2/2-2:1.0/input/input11

By the way, I use the very same CAM daily on for Skype video calls as well as the Camera is working with no problems to save video or pictures inside Cheese

Here is the exact WebCamera model as identified to the kernel:

noah:~# dmesg|grep -i camera
[ 1.433661] usb 2-2: Product: USB2.0 Camera
[ 10.107840] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1e4e:0102)
[ 10.110660] input: USB2.0 Camera as /devices/pci0000:00/0000:00:1d.7/usb2/2-2/2-2:1.0/input/input11

The just installed deb has one binary file only /usr/bin/hasciicam. To test it with the camera I issued:

noah:~# hasciicam -d /dev/video0
HasciiCam 1.0 - (h)ascii 4 the masses! - http://ascii.dyne.org
(c)2000-2006 Denis Roio < jaromil @ dyne.org >
watch out for the (h)ASCII ROOTS

Device detected is /dev/video0
USB2.0 Camera
1 channels detected
max size w[640] h[480] - min size w[48] h[32]
Video capabilities:
VID_TYPE_CAPTURE can capture to memory
!! error in ioctl VIDIOCGMBUF: : Invalid argument

Unfortunately as you see from the output, it failed to detect the web camera model.
The exact camera besides its kernel detection naminf is a cheap external USB 2.0 (fake brand / nonanem) "universal" Web PC Camera (SUPER .3mega pixel)

For those who have a further interest in building and installing hasciicam on other Linux platforms than Debian and Ubuntu or whoever wants to look in the code check check Project webpage is. For those who are less of programmers (like me) the project is written in C programming language and uses aa-lib in order to render the video to ASCII.

On the site you will notice two totally schizophrenic looking pictures of presumably the project head developer …

hasciiart video streamed ASCII screenshot of some crazy looking guy smoking marijuanna or smth

As I read in man hasciicam manual page it's said to be able to generate ascii plain text and html files as well as directly to write the output to console, which later probably can be streamed via the network.
Pitily as it didn't detect my camera I couldn't make some testing of its network capabilities.

A Streaming of ASCII couuld be done through pushing the .html output to a webserver and setting a php or javascript to loop through and refresh the browser over the uploaded files every sec or so.

Also I assume the ASCII video output saved in plain console could be streamed via netcat or some tiny scripted perl or bash script and directly observed via a telnet or ssh connection.
One playful way I can think of checking a stored video without the use of FTP is to login via ssh and do:

$ ssh someuser@somehost
$ watch -n 1 "cat video-ascii.html"

:)

Well something disturbing about hasciicam from a (purely Christian point of view) is it was developed by some kind of non profit organization called RastaSoft on the project website, some of its authors has written JAH BLESS.

As I didn't succeeded seeing it working, I'll be interested to hear if someone who red this article and give it a try can report the web camera model used.

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How to convert file content encoded in windows-cp1251 charset to UTF-8 (with iconv) to be delivered properly encoded to browsing end clients

Wednesday, May 16th, 2012

windows-cp1251 bulgarian to UTF-8 / Encoding Communication Decoding Communication Funny Picture

I have a bunch of old html files all encoded in the historically obsolete Windows-cp1251. Windows-CP1251 used to be common used 7 years ago and therefore still big portions of the web content in Bulgarian / Russian Cyrillic is still transferred to the end users in this encoding.

This was just before the "UTF-8 revolution", where massively people started using UTF-8,
Well it was clear the specific national country text encoding standards will quickly be moved by to UTF-8 – Universal Encoding format which abbreviation stands for (Unicode Transformation Format).

Though UTF-8 was clear to be "the future", many web developers mostly because of their incompetency or using an old sources of learning how to writen in HTML continued to use windows-cp1251 in HTMLs. I'm even convinced, there are still developers out there who are writting websites for Bulgarian / Russian / Macedonian customers using obsolete encodings …

The smarter developers of those accustomed to windows-cp1251, KOI-8R etc. etc., were using the meta tag to specify the type of charset of the web page content with:

<meta http-equiv="content-type" content="text/html;charset=windows-cp1251">

or

<meta http-equiv="content-type" content="text/html;charset=koi-8r">

Anyhow, still many devs even didn't placed the windows-cp1251 in the head of the HTML …

The result for the system administrator is always a mess – a lot of webpages that are showing like unreadable signs and tons of unhappy customers.
As always the system administrator is considered responsible, for the programmer mistakes :) . So instead of programmers fix their bad cooking, the admin has to fix it all!

One quick work around me as admin has applied to failing to display pages in Cyrillic using the Windows-cp1251 character encoding was to force windows-cp1251 as a default encoding for the whole virtualhost or Apache directory with Apache directives like:

<VirtualHost *:80>
ServerAdmin some_user@some_host.com
DocumentRoot /var/www/html
AddDefaultCharset windows-cp1251
ServerName the_host_name.com
ServerAlias www.the_host_name.com
....
....
<Directory>
AddDefaultCharset windows-cp1251
>/Directory>
</VirtualHost>

Though this mostly would, work there are some occasions, where only a particular html files from all the content served by Apache is encoded in windows-cp1251, if most of the content is already written in UTF-8, this could be a big issues as you cannot just change the UTF-8 globally to windows-cp1251, just because few pages are written in archaic encoding….
Since most of the content is displayed to the client by Apache (as prior explained) just fine, only particular htmls lets's ay single.html, single2.html etc. etc. are displayed with some question marks or some non-human readable "hieroglyphs".

Below is a screenshot from two pages returned to my browser in wrongly set htmls charset:

Improper Windows CP1251 encoding with Apache set to serve UTF-8 encoding questiomarks

Improper Windows CP1251 delivered page in UTF-8 browser view

Apache returns cp1251 in some non-UTF8 wrong encoding (webserver improperly served cyrillic encoding)

Improperly served encoding CP1251 delivered by Apache in non-utf-8 encoding

When this kind of issues occur, the only solution is to simply login to the server and use iconv command to convert all files returning unreadable content from whatever the non UTF-8 encoding is lets say in my case Bulgarian typeset of cp1251 to UTF-8

Here is how the iconv command to convert between windows-cp1251 to utf-8 the two sample files named single1.html and single2.html

server:/web# /usr/bin/iconv -f WINDOWS-1251 -t UTF-8 single1.html > single1.html.utf8
server:/web# mv single1.html single1.html.bak;
server:/web# mv single1.html.utf8 single1.html
server:/web# /usr/bin/iconv -f WINDOWS-1251 -t UTF-8 single2.html > single2.html.utf8
server:/web# mv single2.html single2.html.bak;
server:/web# mv single2.html.utf8 single2.html

I always, make copies of the original cp1251 encoded files (as you see mv single1.html single1.html.bak), because if something goes wrong with convertion I can easily revert back.

If there are 10 files with consequential numbers naming they can be converted using a short for loop, like so:

server:/web# for i $(seq 1 10); do
/usr/bin/iconv -f WINDOWS-1251 -t UTF-8 single$i.html > single$i.html.utf8;mv single$i.html single$i.html.bak
mv single$i.html.utf8 single$i.html
done

Just as earlier mentioned if single1.html, single2.html … has in the html <head>:

<meta http-equiv="Content-Type" content="text/html; charset=windows-1251">

You should open, each of the files in question and wipe out the line either by hand or use sed to wipe it in one loop if it has to be done for lets say 10 files named (single{1..10})

server:/web# for i in $(seq 1 10); do
sed '/<meta http-equiv="Content-Type" content="text\/html; charset=windows-1251>/d' single$i.txt > single$i.txt.new;
mv single$i.txt single$i.txt.bak;
mv single$i.txt.new single$i.txt

Well now,

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How to permanently enable Cookies in Lynx text browser – Disable accept cookies prompt in lynx console browser

Wednesday, April 18th, 2012

The default behaviour of lynx console text browser on Linuces, BSD and other free OSes is to always ask, for the accept cookies prompt once an internet web page is opened that requires browser cookies to be enabled.

I should admin, having this "secure by default" (always ask for new cookies) behaviour in lynx was a good practice from a security point of view.

Another reason, why this cookies prompt is enabled by default is back in the days, when lynx was actively developed by programmers the websites with cookies support was not that many and even cookies was mostly required for user/pass authentication (all those who still remember this days the websites that requires authentication was a way less than today) …
With this said the current continuing security cautious behaviour in the browser, left from its old days is understandable.

Screenshot Google Accept cookies Lynx dialog FreeBSD

However I personally sometimes, need to use lynx more frequently and this behaviour of always opening a new website in text mode in console to prompts me for a cookie suddenly becomes a big waste of time if you use lynx to browser more than few sites. Hence I decided to change the default way lynx handles cookies and make them enabled by default instead.
Actually even in the past, when I was mainly using internet in console on every new server or home Linux install, I was again making the cookies to be permanently accepted.
Everyone who used lynx a few times already knows its "annoying" to all time accept cookie prompts … This provoked me to write this short article to explain how enabling of constant cookie accepting in lynx is done

To enable the persistent cookies in lynx, one needs to edit lynx.cfg on different GNU / Linux and BSD* distributions lynx.cfg is located in different directory.

Most of the lynx.cfg usual locations are /etc/lynx/lynx.cfg or /etc/lynx.cfg as of time of writting this post in Debian Squeeze GNU / Linux the lynx.cfg is located in /etc/lynx-cur/lynx.cfg, whether for FreeBSD / NetBSD / OpenBSD users the file is located in /usr/local/etc/lynx.cfg

What I did to allow all cookies is open lynx.cfg in vim edit and change the following lines:

a)

#FORCE_SSL_COOKIES_SECURE:FALSE

with

FORCE_SSL_COOKIES_SECURE:TRUE

b)

#SET_COOKIES:TRUE

uncomment it to:

SET_COOKIES:TRUE

c) next, change

ACCEPT_ALL_COOKIES:FALSE

ACCEPT_ALL_COOKIES:TRUE

Onwards opening any website with lynx auto-accepts the cookies.

lynx Always allowing from domain cookies Linux screenshot

Google in Bulgarian Lynx browser screenshot

For people who care about there security (who still browse in console (surely not many anymore)), permanently allowing the cookies is not a good idea. But for those who are ready to drop off little security for convenience its ok.
 

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Fix Null error in WordPress comment reply with wordpress-threaded-comments plugin enabled

Friday, April 6th, 2012

I'm running WordPress for already 3 years or so now. Since some very long time. The first wordpress install, I can hardly remember but it something like wordpress 2.5 or wordpress 2.4

Since quite a long time my wordpress blog is powered by a number of plugins, which I regularly update, whenever new plugins pops up …
I haven't noticed most of the time problems during major WordPress platform updates or the update of the installed extensions. However, today while I tried to reply back to one of my blog comments, I've been shocked that, I couldn't.
Pointing at the the Comment Reply box and typing inside was impossible and a null message was stayed filled in the form:

To catch what was causing this weird misbehaving with the reply comments functionality, I grepped through my /var/www/blog/wp-content/plugins/* for the movecfm(null,0,1,null):

# cd /var/www/blog/wp-content/plugins
# grep -rli 'movecfm(null,0,1,null)' */*.php
wordpress-thread-comment/wp-thread-comment.php

I've taken the string movecfm(null,0,1,null) from the browser page source in in my Firefox by pressing – Ctrl+U).

Once I knew of the problem, I first tried commenting the occurances of the null fields in wp-thread-comment.php, but as there, were other troubles in commenting this and I was lazy to read the whole code, checked online if some other fellows experienced the same shitty null void javascript error and already someone pointed at a solution. In the few minutes search I was unable to find anyone who reported for this bug, but what I found is some user threads on wordpress.org mentioning since WordPress 2.7+ the wordpress-threaded-comments is obsolete and the functionality provided by the plugin is already provided by default in newer WPinstalls.

Hence in order to enable the threaded comments WordPress (embedded) reply functionality from within the wp-admin panel used:

Settings -> Discussions -> Enable Threaded (nested) comments (Tick)

Enable Nested Comments WordPress default wp comments enable reply functionality screenshot

You see there is also an option to define how many nested comments subcomments, can be placed per comment, the default was 5, but I thought 5 is a bit low so increased it to 10 comments reply possible per comment.

Finally, to prevent the default threaded comments to interfere with the WordPress Threaded Comments plugin, disabled the plugin through menus:

Plugins -> Active -> WordPress Thread Comments (Deactivate)

This solved the weird javascript null "bug" caused by wordpress-threaded-comments once and for all.
Hopefully onwards, my blog readers will not have issues with threaded Reply Comments.

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Finally TeamViewer 7 release for GNU / Linux is available

Thursday, March 29th, 2012

 

TeamViewer 7 Debian GNU / Linux released, my desktop screenshot

After a long time of inavailability, finally TeamViewer 7 for GNU / Linux is out!

Here is the short TeamViewer 7 Linux release note :

In our TeamViewer download area you will now find TeamViewer 7 for Linux.
The final version includes a selection of new features for Linux, e. g. an integrated screenshot feature and the possibility of saving individual connection settings per computer.
You can now establish cross platform connections with other computers running version 7 and hold online meetings and presentations with up to 25 participants.

We wish you best continued success with TeamViewer!

Well, guys it was about time, even later than that… Until now I've so many times experienced troubles with Windows machines which I had to administrate remotely and they only had a TeamViewer 7 installed (a real, real pain in the ass).

The issue comes cause TeamViewer 6 is incompatible with 7 and just until very recently only TV 6 for Linux was available, so trying to access a 7 install directly from Linux was impossible.
Hence to access TeamViewer 7 Windows install, I had to use either a fresh Windows copy with TeamViewer 7 installed or a Virtual Machine like (Qemu, VirtualBox) with Windows version installed in it.
Often back then, when I had to fix remotely a Windows machine behind a firewall, I had to instruct the machine owners to replace the TeamViewer 7 with TeamViewer 6 in order to be able to easily access the remote host from my Debian Linux.

I still remember, it was quite a stuggle to find a link to a Windows .exe install file for TeamViewer 6.

Now thanksfully, TeamViewer guys are starting to make it easier for the user who would for some reason want to stick to older TV version.
I've noticed on TeamViewer's website there is already a new TeamViewer download page offering for download all the old teamviewer version – 1.x, 2.x, 3.x, 4.x, 5.x, 6.x

One example, where old teamviewer release is useful is if you want to run teamviewer on older hardware or old OS (MS Windows 98 or old Linux distro).

I've made a mirror of teamviewer 6 for Debian / Ubuntu amd 32 and 64 bit versions along with all the OS available TeamViewer version 6 and 7, for the sake of preserving it if one day link to old versions of Teamviewer disappear from their website.

Here are the TeamViewer mirrored files:

Below you see a screenshot of teamviewer 7 running on my Debian Squeeze :)

TeamViewer 7 Debian GNU / Linux released, my desktop screenshot

It is great teamviewer produced a Linux working application, however if you run it you realize just like the previous releases TeamViewer is not natively supposed (compiled) to run on GNU / Linux OS but uses wine (windows emulator) to launch through…
Instead of porting the application to be natively for the Linux distros once again with this new release, teamviewer developers just "hacked" it to run on top of windows emulation. Though this is working its performance, is probably a bit degraded and it depends on having install on the Linux host a bunch of useless packages which wine depends on.
Besides that even if it "works" on Linux , TeamViewer has still non-free software essense. I still use it because unfortunately, I don't know of a better remote access program capable to connect to servers behind NAT / machines located behind a tight firewalled routers.
If only (I knew of?) a TeamViewer free software / open source equivalent
I will be glad to hear if someone know a (free software / open source) TeamViewer like program able to access remote hosts with no a real (public inet) IP address?P.S.: By similar TV program I don't mean VNC, UltraVNC and this kind of other VNC derivative programs but mean close TeamViewer alternative.

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Tracking I/O hard server bottlenecks with iostat on GNU / Linux and FreeBSD

Tuesday, March 27th, 2012

Hard disk overhead tracking on Linux and FreeBSD with iostat

I've earlier wrote an article How to find which processes are causing hard disk i/o overhead on Linux there I explained very rawly few tools which can be used to benchmark hard disk read / write operations. My prior article accent was on iotop and dstat and it just mentioned of iostat. Therefore I've wrote this short article in attempt to explain a bit more thoroughfully on how iostat can be used to track problems with excessive server I/O read/writes.

Here is the command man page description;
iostatReport Central Processing Unit (CPU) statistics and input/output statistics for devices, partitions and network filesystems

I will further proceed with few words on how iostat can be installed on various Linux distros, then point at few most common scenarious of use and a short explanation on the meaning of each of the command outputs.

1. Installing iostat on Linux

iostat is a swiss army knife of finding a server hard disk bottlenecks. Though it is a must have tool in the admin outfut, most of Linux distributions will not have iostat installed by default.
To have it on your server, you will need to install sysstat package:

a) On Debian / Ubuntu and other Debian GNU / Linux derivatives to install sysstat:

debian:~# apt-get --yes install sysstat

b) On Fedora, CentOS, RHEL etc. install is with yum:

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

c) On Slackware Linux sysstat package which contains iostat is installed by default. 

d) In FreeBSD, there is no need for installation of any external package as iostat is part of the BSD world (bundle commands).
I should mention bsd iostat and Linux's iostat commands are not the same and hence there use to track down hard disk bottlenecks differs a bit, however the general logic of use is very similar as with most tools in BSD and Linux.

2. Checking a server hard disk for i/o disk bottlenecks on G* / Linux

Once having the sysstat installed on G* / Linux systems, the iostat command will be added in /usr/bin/iostat
a) To check what is the hard disk read writes per second (in megabytes) use:

debian:~# /usr/bin/iostat -m
Linux 2.6.32-5-amd64 (debian) 03/27/2012 _x86_64_ (8 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
15.34 0.36 2.76 2.66 0.00 78.88
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
sda 63.89 0.48 8.20 6730223 115541235
sdb 64.12 0.44 8.23 6244683 116039483
md0 2118.70 0.22 8.19 3041643 115528074

In the above output the server, where I issue the command is using sda and sdb configured in software RAID 1 array visible in the output as (md0)

The output of iostat should already be easily to read, for anyone who didn't used the tool here is a few lines explanation of the columns:

The %user 15.34 meaning is that 15.34 out of 100% possible i/o load is generad by system level read/write operations.
%nice – >Show the percentage of CPU utilization that occurred while executing at the user level with nice priority.
%iowait – just like the top command idle it shows the idle time when the system didn't have an outstanding disk I/O requests.
%steal – show percentage in time spent in time wait of CPU or virtual CPUs to service another virtual processor (high numbers of disk is sure sign for i/o problem).
%idle – almost the same as meaning to %iowait
tps – HDD transactions per second
MB_read/s (column) – shows the actual Disk reads in Mbytes at the time of issuing iostat
MB_wrtn/s – displays the writes p/s at the time of iostat invocation
MB_read – shows the hard disk read operations in megabytes, since the server boot 'till moment of invocation of iostat
MB_wrtn – gives the number of Megabytes written on HDD since the last server boot filesystem mount

The reason why the Read / Write values for sda and sdb are similar in this example output is because my disks are configured in software RAID1 (mirror)

The above iostat output reveals in my specific case the server is experiencing mostly Disk writes (observable in the high MB_wrtn/s 8.19 md0 in the above sample output).

It also reveals, the I/O reads experienced on that server hard disk are mostly generated as a system (user level load) – see (%user 15.34 and md0 2118.70).

For all those not familiar with system also called user / level load, this is all kind of load which is generated by running programs on the server – (any kind of load not generated by the Linux kernel or loaded kernel modules).

b) To periodically keep an eye on HDD i/o operations with iostat, there are two ways:

- Use watch in conjunction with iostat;

[root@centos ~]# watch "/usr/bin/iostat -m"
Every 2.0s: iostat -m Tue Mar 27 11:00:30 2012
Linux 2.6.32-5-amd64 (centos) 03/27/2012 _x86_64_ (8 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
15.34 0.36 2.76 2.66 0.00 78.88
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
sda 63.89 0.48 8.20 6730255 115574152
sdb 64.12 0.44 8.23 6244718 116072400
md0 2118.94 0.22 8.20 3041710 115560990
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
sda 55.00 0.01 25.75 0 51
sdb 52.50 0.00 24.75 0 49
md0 34661.00 0.01 135.38 0 270

Even though watch use and -d might appear like identical, they're not watch does refresh the screen, executing instruction similar to the clear command which clears screen on every 2 seconds, so the output looks like the top command refresh, while passing the -d 2 will output the iostat command output on every 2 secs in a row so all the data is visualized on the screen. Hence -d 2 in cases, where more thorough debug is necessery is better. However for a quick routine view watch + iostat is great too.

c) Outputting extra information for HDD input/output operations;

root@debian:~# iostat -x
Linux 2.6.32-5-amd64 (debian) 03/27/2012 _x86_64_ (8 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
15.34 0.36 2.76 2.66 0.00 78.88
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util
sda 4.22 2047.33 12.01 51.88 977.44 16785.96 278.03 0.28 4.35 3.87 24.72
sdb 3.80 2047.61 11.97 52.15 906.93 16858.32 277.05 0.03 5.25 3.87 24.84
md0 0.00 0.00 20.72 2098.28 441.75 16784.05 8.13 0.00 0.00 0.00 0.00

This command will output extended useful Hard Disk info like;
r/s – number of read requests issued per second
w/s – number of write requests issued per second
rsec/s – numbers of sector reads per second
b>wsec/s – number of sectors wrote per second
etc. etc.

Most of ppl will never need to use this, but it is good to know it exists.

3. Tracking read / write (i/o) hard disk bottlenecks on FreeBSD

BSD's iostat is a bit different in terms of output and arguments.

a) Here is most basic use:

freebsd# /usr/sbin/iostat
tty ad0 cpu
tin tout KB/t tps MB/s us ni sy in id
1 561 45.18 44 1.95 14 0 5 0 82

b) Periodic watch of hdd i/o operations;

freebsd# iostat -c 10
tty ad0 cpu
tin tout KB/t tps MB/s us ni sy in id
1 562 45.19 44 1.95 14 0 5 0 82
0 307 51.96 113 5.73 44 0 24 0 32
0 234 58.12 98 5.56 16 0 7 0 77
0 43 0.00 0 0.00 1 0 0 0 99
0 485 0.00 0 0.00 2 0 0 0 98
0 43 0.00 0 0.00 0 0 1 0 99
0 43 0.00 0 0.00 0 0 0 0 100
...

As you see in the output, there is information like in the columns tty, tin, tout which is a bit hard to comprehend.
Thanksfully the tool has an option to print out only more essential i/o information:

freebsd# iostat -d -c 10
ad0
KB/t tps MB/s
45.19 44 1.95
58.12 97 5.52
54.81 108 5.78
0.00 0 0.00
0.00 0 0.00
0.00 0 0.00
20.48 25 0.50

The output info is quite self-explanatory.

Displaying a number of iostat values for hard disk reads can be also achieved by omitting -c option with:

freebsd# iostat -d 1 10
...

Tracking a specific hard disk partiotion with iostat is done with:

freebsd# iostat -n /dev/ad0s1a
tty cpu
tin tout us ni sy in id
1 577 14 0 5 0 81
c) Getting Hard disk read/write information with gstat

gstat is a FreeBSD tool to print statistics for GEOM disks. Its default behaviour is to refresh the screen in a similar fashion like top command, so its great for people who would like to periodically check all attached system hard disk and storage devices:

freebsd# gstat
dT: 1.002s w: 1.000s
L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name
0 10 0 0 0.0 10 260 2.6 15.6| ad0
0 10 0 0 0.0 10 260 2.6 11.4| ad0s1
0 10 0 0 0.0 10 260 2.8 12.5| ad0s1a
0 0 0 0 0.0 0 0 0.0 20.0| ad0s1b
0 0 0 0 0.0 0 0 0.0 0.0| ad0s1c
0 0 0 0 0.0 0 0 0.0 0.0| ad0s1d
0 0 0 0 0.0 0 0 0.0 0.0| ad0s1e
0 0 0 0 0.0 0 0 0.0 0.0| acd0

It even has colors if your tty supports colors :)

Another useful tool in debugging the culprit of excessive hdd I/O operations is procstat command:

Here is a sample procstat run to track (httpd) one of my processes imposing i/o hdd load:

freebsd# procstat -f 50404
PID COMM FD T V FLAGS REF OFFSET PRO NAME
50404 httpd cwd v d -------- - - - /
50404 httpd root v d -------- - - - /
50404 httpd 0 v c r------- 56 0 - -
50404 httpd 1 v c -w------ 56 0 - -
50404 httpd 2 v r -wa----- 56 75581 - /var/log/httpd-error.log
50404 httpd 3 s - rw------ 105 0 TCP ::.80 ::.0
50404 httpd 4 p - rw---n-- 56 0 - -
50404 httpd 5 p - rw------ 56 0 - -
50404 httpd 6 v r -wa----- 56 25161132 - /var/log/httpd-access.log
50404 httpd 7 v r rw------ 56 0 - /tmp/apr8QUOUW
50404 httpd 8 v r -w------ 56 0 - /var/run/accept.lock.49588
50404 httpd 9 v r -w------ 1 0 - /var/run/accept.lock.49588
50404 httpd 10 v r -w------ 1 0 - /tmp/apr8QUOUW
50404 httpd 11 ? - -------- 2 0 - -

Btw fstat is sometimes helpful in identifying the number of open files and trying to estimate which ones are putting the hdd load.
Hope this info helps someone. If you know better ways to track hdd excessive loads on Linux / BSD pls share 'em pls.
 

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What is the facebook recommended profile picture (logo) size for better SEO Marketing / Few basic Facebook marketing tips

Wednesday, February 29th, 2012

Facebook marketing Likes good recommended logo sizes, Facebook profile logo

I hate facebook, from the deepness of my guts! However, unfortunately in one of the companies I'm employed, occasionally I have to use it as an advertisement media to improve the Search Engine visibility for their websites (gather them some more likes). As a not big lover of facebook, I'm also not a facebook-pro, anyways with this circumstances, I'm starting to learn basic tips on, making a facebook page / profile more user friendly and hence more attracting to facebook users.

From what, i"ve read there are plenty of factors that can affect on how attractive a facebook page / company profile , anyways some of the factors are more important to tamper than others. Such two factors of top importance are:
 

Let me evaluate a bit on each of the three aforementioned fb marketing weight factors.

1. Using Page likes for popularization.

- Lets say that you would like to make marketing to a company websites which is involved in Financial or Investment market.
Enter with the company created page or profile and facebook and think for and search for as many keywords related to the company business as possible.
Check each of the results if the Page / Group is liked by hundred thousands of other people, then just give it a like too.
By doing so for a couple of seconds all this (hundred thousands or millions) of people who has also liked it will see for a second (or less), what hangs on your Facebook profile ;)
The chance someone gets interested into what is your profile saying here is high especially if this pops up to a some 100 000+ of logged people who previously liked a fb page :)

2. Joining groups as a way to drive more visitors to a facebook profile

Joining big groups consisting ot thousands or millions's logic is the same like with the page likes. The only difference is some groups are kept private the so called (Closed Group).
Finding a number of similar (Open Groups) to your company activities and joining them will possibly display your company facebook profile to as many profiles as the group has.
Most of the groups are not too active therefore joing groups as a way to drive attention of facebook users to a desired profile is not so efficient as with Page Likes Adjusting a profile picture logo dimensions to a wide skyscraper.

It might seem strange but actually the size of profile picture set to pages or profiles in facebook matters, different profiles dimensions could have impact on Page Likes :)
The reason for the fb picture profile having influence on the marketing is very simple. If you have a wider picture you can graphically include more data visible for the user that is always stuck to the page and hence seen by the user.

I've realized this after, I've red few articles online on the same topic along with that I've noticed many big brand pages on Facebook like for instance BMW (Cars) with over 8 000 000 of likes, Adidas and Nike – with over 6 000 000 likes, have set up this wide skyscraper dimensions logos.

Here is a crop taken displaying the wide skyscraper profile picture set by BMW cars.The profile picture used by BWM (cars) has an image dimensions of: 180×500 heigh x widthAdidas's profile logo has a size of 180×489.

Nike uses a bit of unstandard 390×720 (but while uploaded facebook website automatically crops the image to a size which is fittable for a wide skyscraper) with dimensions like (200×400)Another franchising company with big likes base, I've seen is McDonald's with 19 900 000+ likes! again with a banner logo consisting of wide scraper with picture dimenions (180×439 – height / width )There are some comparatively big user base facebook pages, like Ubuntu's non-profit organization with 555 000+ thousands of likes, and their logo has dimensions of 180×181 pixels.

Not all of the highly liked (visited) facebook pages however use a wide skyscraper as a profile logo and still has enormous number of likes.
One contra-example showing that there is no clear relation between facebook profile picture dimensions and page popularity (number of likes) is Metallica (Musician/Band) fan page – (http://www.facebook.com/Metallica), which as of the time of writting this article has the UNIQUE HIGH NUMBER of 23,725,897 LIKES! :)

As far as, I've further red on many blogs, there are two general facebook standard banner profile picture recommendations:

 

1. One is facebook square like profile picture

- (this is the classics), if you just place a picture that is not too wide automatically facebook upload scripts will tailer the picture to have dimensions like: 180×180 pixels

The other recommended facebook pictures size is the wide wide-scraper and it should possess an image dimensions size similar to:
width x height -180×500 pixels

This is pretty much the few basics I  so far, know of can help to easily gather a custom fb company Page Likes.
As facebook is really HUGE nowdays  fb marketing has advanced tremendously.

I'll be glad to hear some cool tips & tricks you know? which can help a facebook page / profile popularity rise up.
Looking forward to hear for your good or bad facebook experiences :)

  • Likes of pages, which are liked by thousands of hundreds or millions of people
  • Belongings to groups / Membering to big groups (consisting of thousands)
    which hold similar interest or business activity
  • Profile picture logo dimensions

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