abhionlinux

Softaculous : Your license is not active or it has expired. If your license has expired, please renew it to continue using this Software.

2012-01-12T17:06:00.000+05:30

If you want to synchronize your license after purchasing one, click on the Refresh License link in your Softaculous Admin Panel. That will syncronize your license information. To synchronize the Scripts / Software, go to the Software Tab in your Softaculous Admin Panel and click on "Update Settings". You will see a log of all scripts being updated.

Softaculous syncronizes with servers for files and License information when CRON is run. You can force CRON to run via some shell commands to imediately sychronize for the License Information or for Script Files. These commands vary from panel to panel so please run the commands as per your Panel.

For cPanel SSH to your server as root and enter following commands

/usr/local/cpanel/3rdparty/bin/php /usr/local/cpanel/whostmgr/docroot/cgi/softaculous/cron.php

How to change the time zone for a domain

2011-12-22T21:35:00.000+05:30

You can change the time zone for a domain in a shared server.

If the server php is compiled with Apache (dso module)
You can use htaccess to set the time zone for a domain.

SetEnv TZ location

For suphp servers,
You need to create custom php.ini for your domain and add the following

date.timezone = "location"

You can get the time zones from http://www.php.net/manual/en/timezones.php

special device device-name does not exist : LVM

2011-12-22T21:17:00.000+05:30

OS in my server's hard disk got corrupted. Only way to retrieve data is perform an OS reload in a new harddisk and connect the old hard disk as secondary. My drives are LVM. I have done OS reload on the new hard disk and connected the old one as secondary. When I try to mount the old hard disk, I am getting the error "special device *device-name* does not exist"

You can check the number of hard-disk connected to your server using fdisk -l.

I am trying to mount the old drive using the command.
mount /dev/VolGroup02/LogVol00 /old

/dev/VolGroup02/LogVol00 is the volomegroup name for the old hard disk.

Issue was when the new harddisk has been done with OS reload, its volume group name was /dev/VolGroup01/LogVol00. Old harddisk volume group was already /dev/VolGroup01/LogVol00

When an os reload is performed, volume group for that drive will be /dev/VolGroup01/LogVol00. This will be done by default. When old harddisk volumegroup name and new harddisk volume group name became same, conflict occurs and can mount the old drive. What we have done is changed the volume group name for old drive to /dev/VolGroup02/LogVol00

After that when we try to mount that old drive getting the error special device *device-name* does not exist.

You can fix it using the command

vgchange -ay  /dev/VolGroup02/LogVol00

"vgchange -ay" is to activate all known volume groups in the system.
vgchange allows you to change the attributes of one or more volume groups.

-a Controls the availability of the logical volumes in the volume group for input/output. In other
words, makes the logical volumes known/unknown to the kernel.

Site error: the file /usr/local/cpanel/whostmgr/docroot/cgi/softaculous/enduser/main/functions.php requires the ionCube PHP Loader ioncube_loader_lin_5.2.so to be installed by the site administrator. - Softaculous

2011-12-14T17:25:00.000+05:30

When we select Softaculous - Instant Installs under plugins option in WHM, you may get the error
"Site error: the file /usr/local/cpanel/whostmgr/docroot/cgi/softaculous/enduser/main/functions.php requires the ionCube PHP Loader ioncube_loader_lin_5.2.so to be installed by the site administrator."

Solution:
If you are getting this error, make sure that you have installed ioncube loader in your server. You can do this using /scripts/easyapache

Still you are getting the error after installing ioncube loader, You have to enable cPanels backend ioncube loader (WHM > Tweak settings > Loader to use for internal cPanel PHP).

Hope this will fix your issue.

RKhunter installation

2011-11-20T05:39:00.000+05:30

RKhunter is a tool used to scan the server for rootkits, backdoors and local exploits.

Steps to install RKhunter:

1. Download from

wget http://sourceforge.net/projects/rkhunter/files/latest/download?source=files

2 Extract it
tar -xvzf rkhunter-1.3.8.tar.gz

3. cd rkhunter-1.3.8

4. Run the installation command as given below.
./installer.sh --layout default --install

/usr/local/bin/rkhunter --update

/usr/local/bin/rkhunter --propupd

/usr/local/bin/rkhunter -c

Kaltura Installation

2011-11-06T01:07:00.000+05:30

Kaltura is an open source video platform, video solutions, software and services for video publishing, management and monetization. It is mainly used in video hosting.
Following are the steps to install kalture in a cpanel server (Centos 5.6)

Pre-requisites:
1. Suphp and suexec should be disable for effective working of Kaltura.
2. ini_set should be enable in php.ini
3. Php modules such as Exif, Mysqli, Iconv should be enabled in the server. This can be done using easyapache.
4. Apache module such as file_cache should be enabled .
5. Suhosin should be disabled in the server
6. Memcached and Pentaho should be installed.
7. Set 'lower_case_table_names = 1' in my.cnf and restart MySQL
8. Mysql root password should be taken. You can get this from the file /root/.my.cnf

Installation:
You can download the Kaltura installation file from Kaltura official website. Once the installation files is recieved, unzip that file. You can see a file called "install.php"

Login to the server as root and run the command given below.
php install.php

This will be asking certian questions such as

1. In order to improve Kaltura Community Edition, we would like your permission to send system data to Kaltura. This information will be used exclusively for improving our software and our service quality. I agree (Y/n) Y
2. If you wish, please provide your email address so that we can offer you future assistance (leave empty to pass): admin@abhionliux.in
3. The following apachectl script has been detected: /usr/sbin/apachectl. Do you want to use this script to run your Kaltura application? Leave empty to use or provide a pathname to an alternative apachectl script on your server.
Leave it as empty
4. The following PHP binary has been detected: /usr/local/bin/php. Do you want to use this script to run your Kaltura application? Leave empty to use or provide a pathname to an alternative PHP binary on your server.
Leave it as empy
5. Full target directory path for Kaltura application (leave empty for /opt/kaltura)

Leave it as empy

6. Please enter the domain name/virtual hostname that will be used for the Kaltura server (without http://)

abhionlinux.co.cc

7 . Your primary system administrator email address

admin@abhionlinux.co.cc

8. The password you want to set for your primary administrator

*********

9. Database host (leave empty for 'localhost')

Leave empty

10. Database port (leave empty for '3306')

Leave empty

11. Database username (with create & write privileges)

root

12. Database password (leave empty for no password)

rootpassword

13. The URL to your xymon/hobbit monitoring location. Xymon is an optional installation. Leave empty to set manually later

Leave Empty

You will get the following message.

============================================

Installation Completed Successfully.

Your Kaltura Admin Console credentials:

System Admin user: admin@abhionlinux.co.cc

System Admin password: admin123

Please keep this information for future use.

To start using Kaltura, please complete the following steps:

1. Add the following line to your /etc/hosts file:

127.0.0.1 abhionlinux.co.cc

2. Add the following line to your Apache configurations file (Usually called httpd.conf or apache2.conf):

Include /opt/kaltura/app/configurations/apache/my_kaltura.conf

3. Restart apache

4. Browse to your Kaltura start page at: http://abhionlinux.co.cc/start

==============================================

Once you get this message, open the file /opt/kaltura/app/configurations/apache/my_kaltura.conf and you need to replace the * with the IP address

Eg : VirtualHost *:80

This should be replaced by VirtualHost 192.168.0.10:80

Now you can access kalture using http://abhionlinux.co.cc/start

ffmpeg-php installation

2011-09-19T17:17:00.001+05:30

Download the latest ffmpeg-php. You can download it using

# wget http://sourceforge.net/projects/ffmpeg-php/files/ffmpeg-php/0.6.0/ffmpeg-php-0.6.0.tbz2/download
# tar -xvjf ffmpeg-php-0.6.0.tbz2
# phpize
# ./configure --enable-shared
# make
# make install

Once the installation is completed, you need to add the ffmpeg.so file in your php.ini

Locate you php.ini using
# php -i | grep php.ini
Configuration File (php.ini) Path => /usr/local/lib
Loaded Configuration File => /usr/local/lib/php.ini

# vi /usr/local/lib/php.ini

add the following line to your php.ini file.
extension=”ffmpeg.so”

restart apache
#/etc/init.d/http restart

You can check the ffmpeg-php module using the command

# php -m | grep ffmpeg
ffmpeg

Common issues in installing ffmpeg-php
1. While running make, you will get an error

make: *** [ffmpeg_frame.lo] Error 1

Fix: Copy the file ffmpeg_frame.loT to ffmpeg_frame.lo

#cp ffmpeg_frame.loT ffmpeg_frame.lo

This should fix the above issue.

2. After enabling ffmpeg in php.ini, you can get an error

php: symbol lookup error: /usr/local/lib/php/extensions/no-debug-non-zts-

20060613/ffmpeg.so: undefined symbol: register_ffmpeg_frame_class

Fix : Goto ffmpeg-php installation folder and open the file ffmpeg_frame.c and replace all

PIX_FMT_RGBA32 with PIX_FMT_RGB32

cd /usr/local/src/ffmpeg-php

# vi ffmpeg_frame.c

:%s/PIX_FMT_RGBA32/PIX_FMT_RGB32

:wq!

then you need to compile ffmpeg

#./configure --enable-shared

#make

#make install

Hope this will help you in installing ffmpeg-php in your server.

flvtool2

2011-09-19T02:58:00.004+05:30

wget http://rubyforge.org/frs/download.php/17497/flvtool2-1.0.6.tgz

cd /usr/local/src/flvtool2-1.0.6/
ruby setup.rb config
ruby setup.rb setup
ruby setup.rb install

create db and user in mysql

2011-09-19T02:46:00.001+05:30

mysql -u root -p
mysql> create database db;
Query OK, 1 row affected (0.00 sec)

mysql> grant all privileges on amarokdb.* to amarokuser@localhost identified by 'passwd';
Query OK, 0 rows affected (0.00 sec)

FFmpeg installation

2011-09-19T02:45:00.000+05:30

Installing a52

# wget http://liba52.sourceforge.net/files/a52dec-0.7.4.tar.gz

# tar -zxf a52dec-0.7.4.tar.gz

# cd a52dec-0.7.4

# ./configure --enable-shared=PKGS

# make

# make install

# wget http://sourceforge.net/projects/faac/files/faac-src/faac-1.28/faac-1.28.tar.gz/download

# tar -xvzf faac-1.28.tar.gz

# ./bootstrap

# ./configure

# make

# make install

# cd ..

installing faad

# wget http://sourceforge.net/projects/faac/files/faad2-src/faad2-2.7/faad2-2.7.tar.gz/download

# tar -xvzf faad2-2.7.tar.gz

]# autoreconf -vif

# ./configure --disable-drm --disable-mpeg4ip

# make

# make install

installing lame:

# wget http://sourceforge.net/projects/lame/files/lame/3.98.4/lame-3.98.4.tar.gz/download

# tar -xvzf lame-3.98.4.tar.gz

# ./configure

# make

# make install

intall yasm

# wget http://www.tortall.net/projects/yasm/releases/yasm-1.1.0.tar.gz

# tar -xvzf yasm-1.1.0.tar.gz

]# ./configure

#make

# make install

x264

git clone git://git.videolan.org/x264.git

./configure --enable-shared --prefix=/usr

make

make install

xvidcore

wget http://downloads.xvid.org/downloads/xvidcore-1.3.2.tar.gz

tar -xvzf xvidcore-1.3.2.tar.gz

cd build/generic/

./configure

make

make install

http://www.xvid.org/Downloads.43.0.html

svn co https://xavs.svn.sourceforge.net/svnroot/xavs/trunk xavs

./configure

make

make install

libraw installation

wget http://sourceforge.net/projects/libraw1394/files/libraw1394/libraw1394-2.0.5.tar.gz/download

tar -xvzf libraw1394-2.0.5.tar.gz

./configure

make

make install

wget http://sourceforge.net/projects/libdc1394/files/libdc1394-2/2.1.2/libdc1394-2.1.2.tar.gz/download

./configure

make

make install

wget http://sourceforge.net/projects/opencore-amr/files/opencore-amr/0.1.2/opencore-amr-0.1.2.tar.gz/download

./configure

make

make install

mplayerhq.hu/MPlayer/releases/codecs/essential-20071007.tar.bz2

echo y | cp * /usr/local/lib/codecs/

echo y | cp * /usr/local/lib64/codecs/

libogg

wget http://downloads.xiph.org/releases/ogg/libogg-1.3.0.tar.gz

./configure

make

make install

libvorbis

wget http://downloads.xiph.org/releases/vorbis/libvorbis-1.3.2.tar.gz

./configure

make

make install

wget http://downloads.xiph.org/releases/theora/libtheora-1.1.1.tar.gz

tar -xvzf libtheora-1.1.1.tar.gz

./configure

make

make isntall

export LD_LIBRARY_PATH=/usr/local/lib/

echo /usr/local/lib > /etc/ld.so.conf.d/custom-libs.conf

yum install dirac dirac-devel

./configure --enable-version3 --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libvpx --enable-libfaac --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --disable-ffplay --enable-shared --enable-gpl --enable-postproc --enable-nonfree --enable-avfilter --enable-pthreads --extra-cflags=-fPIC

MP4Box installation

2011-09-16T16:16:00.001+05:30

Follow the steps given below to install MP4Box

#cd /usr/local/src/

# wget http://nchc.dl.sourceforge.net/project/gpac/GPAC/GPAC%200.4.5/gpac-0.4.5.tar.gz

# wget http://nchc.dl.sourceforge.net/project/gpac/GPAC%20extra%20libs/GPAC%20extra%20libs%200.4.5/gpac_extra_libs-0.4.5.tar.gz

# tar -zxvf gpac-0.4.5.tar.gz

# tar -zxvf gpac_extra_libs-0.4.5.tar.gz

# cd gpac_extra_libs

# cp -r * /usr/local/src/gpac/extra_lib

# cd gpac

# chmod 755 configure

# ./configure

# make lib

# make apps

# make install lib

# make install

# cp bin/gcc/libgpac.so /usr/lib

# which MP4Box
/usr/local/bin/MP4Box

Missing pentaho while installing Kaltura

2011-06-30T02:29:00.000+05:30

While installing Kaltura on your centos 5.6 64 bit server, you can see the error
"Missing pentaho"

Fix:
# mkdir /usr/local/pentaho
# wget http://sourceforge.net/projects/pentaho/files/Data%20Integration/3.2.0-stable/pdi-ce-3.2.0-stable.tar.gz
# tar xvzf pdi-ce-3.2.0-stable.tar.gz
# mv data-integration pdi

ref: https://github.com/instructure/canvas-lms/wiki/Kaltura-setup-instructions

how to install memcached on centos

2011-06-27T04:25:00.001+05:30

You can use the command given below to find the centos version.

# cat /etc/redhat-release

Dependency that is needed for memcached is libevent. First we will proceed with libevent.
Steps for installation libevent.
# cd /usr/local/src/

# curl -O http://monkey.org/~provos/libevent-1.4.14b-stable.tar.gz

# tar xzvf libevent-1.4.14b-stable.tar.gz

# cd libevent-1.4.14b-stable

# ./configure --prefix=/usr/local/

# make

# make install

Next we need to install memcached.

# cd /usr/local/src

# curl -O http://memcached.googlecode.com/files/memcached-1.4.5.tar.gz

# tar -xvzf memcached-1.4.5.tar.gz

# cd memcached-1.4.5

# LDFLAGS='-Wl,--rpath /usr/local/lib' ./configure --prefix=/usr/local

# make

# make install

You can verify the memcache using the command

# memcached -u root -d

If there are no errors, memcache is successfully installed and is running.

# ps aux | grep memcached

Note:

memcached: error while loading shared libraries: libevent-1.4.so.2: 
  cannot open shared object file: No such file or directory
  configure: error: libevent is required
  If it's already installed, specify its path using --with-libevent=/dir/

Install php-memcache

Please try the following steps
# wget http://pecl.php.net/get/memcache-3.0.3.tgz
# tar -xvzf memcache-3.0.3.tgz
# cd memcache-3.0.3
# phpize
#./configure
# make
# make install

Open php.ini
# vi /etc/php.ini
add the line given below.
extension=memcache.so

Then restart apache. You can check this my "php -m | grep memcache"

How to reset a kloxo admin password

2011-06-27T04:16:00.000+05:30

If you have forgot the kloxo admin password , you can try the following fix.

You should have root access to the server.
1. Ssh to the server as root.
2. Run the commands given below.

# cd /usr/local/lxlabs/lxadmin/httpdocs
# /usr/bin/lphp.exe ../bin/common/resetpassword.php admin

You can use the password admin as your kloxo admin password.

Clipbucket admin area showing blank page

2011-06-24T00:23:00.000+05:30

When trying to access admin area of clipbucket , we will get blank page,

Fix:
First step we need to check is permission. Make sure that all your files and folders are having 644 and 755 respectively. Still the issue persists, go to step2

Next step is to fix out the file ClipBucket.class.php and search for the line

" function get_cb_news()
{ "

Below this line, you need to add the following line

"return true "

Try this and your issue will be fixed.

Connection to the server was reset - PHPmotion

2011-06-22T12:30:00.000+05:30

Hello,

When you are trying to upload the larger videos in phpmotion, you may have got this error.

http://yourdomain.com/cgi-bin/uu_upload.pl?tmp_sid=815e201755c87c014ef49917cd76a186

The connection to the server was reset while the page was loading.

The network link was interrupted while negotiating a connection. Please try again

Fix:

Issue may be due to apache or php getting timedout. You can fix by increasing the value Timeout in httpd.conf.

SERVICE CURRENTLY NOT AVAILABLE! - Roundcube

2011-06-10T15:06:00.002+05:30

Hello,

If you are getting this error "SERVICE CURRENTLY NOT AVAILABLE!" while accessing roundcube mail, you can fix it by /usr/local/cpanel/bin/update-roundcube --force

How to install memcache in the server

2011-05-25T04:37:00.000+05:30

You can use the steps below to install memcache

cd /usr/local/src/
wget http://www.monkey.org/~provos/libevent-1.4.13-stable.tar.gz
tar -xvf libevent-1.4.13-stable.tar.gz
cd libevent-1.4.13-stable
./configure
make
make install

cd ..
wget http://memcached.googlecode.com/files/memcached-1.4.5.tar.gz

tar -xvf memcached-1.4.5.tar.gz
cd memcached-1.4.5
./configure && make
make install

vi /etc/ld.so.conf.d/libevent-i386.conf
create this file and add one line -> # /usr/local/lib/

/sbin/ldconfig

start your memcached server up

/usr/local/bin/memcached -u nobody &

you should add this last command to /etc/rc.local so the memcached server starts if there is a reboot

How to clear cache memory(RAM) in linux

2011-05-17T10:12:00.002+05:30

Clear cache memory.

You can use the command given below to clear the pagecache
echo 1 > /proc/sys/vm/drop_caches

To free dentries and inodes, you can use the command
echo 2 > /proc/sys/vm/drop_caches

To free pagecache, dentries and inodes:
echo 3 > /proc/sys/vm/drop_caches

.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable

2011-05-14T21:51:00.000+05:30

Is some cases, while browsing your domain you will be getting forbidden page. This is the problem with the directory / files permissions.

From /var/www/vhosts/domain.com/statistics/logs/error_log : You can get the error

[critical] [client 192.168.1.1] (13)Permission
denied: /var/www/vhosts/domain.com/httpdocs/.htaccess pcfg_openfile:
unable to check htaccess file, ensure it is readable

This is due to incorrect permission for the httpdocs/httpsdocs

cd /var/www/vhosts/domain.com/
chmod 755 httpdocs
chmod 755 httpsdocs

This will work for you.

FFmpeg :: make: *** [ffmpeg_frame.lo] Error 1

2011-05-14T17:35:00.000+05:30

When you try to install ffmpeg-php module in the server, you can get the error
FFmpeg :: make: *** [ffmpeg_frame.lo] Error 1

There are two fixes for this issue. Try the first one, if it doesnt fix then go to second.

Fix 1:

In the latest ffmpeg-php, you need to modify the file ffmpeg_frame.c
Usually location will be /usr/src/ffmpeginstaller/ffmpeg-php-0.6.0/ffmpeg_frame.c

Open the above mentioned file and replace every instance of PIX_FMT_RGBA32 with PIX_FMT_RGB32

Then try to configure it,.

./configure
make
make install

Fix 2:
If the fix1 didnt fix the issue, you can follow this one.

You need to just copy the file ffmpeg_frame.loT to ffmpeg_frame.lo

cd /path/to/ffmpeg-php-0.6.0 ie cd /usr/src/ffmpeginstaller/ffmpeg-php-0.6.0
cp ffmpeg_frame.loT ffmpeg_frame.lo
make clean
./configure

This should fix the issue/

How to restore mysql database in linux plesk

2011-05-14T16:37:00.002+05:30

You can use the command 'mysql' to restore the database. Exact command is given below.

mysql -u admin -p`cat /etc/psa/.psa/shadow` database_name < database_dump.sql

How to install commands host, dig and nslookup in linux.

2011-05-12T02:44:00.000+05:30

In a new linux server, when you try to run the command given below, it will be getting error.

[root@server /]# host abhionlinux.in
-bash: host: command not found

In such cases, you need to install the bind-utils package in the server.

1. ssh to the server.
2 run the command
[root@server /]# yum install bind-utils

Now host, dig and nslookup will be working fine.

How to check open ports in linux

2011-05-08T20:27:00.001+05:30

nmap -sS -O 127.0.0.1

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2011-05-08 16:49 CEST
Interesting ports on server.abhi.com (127.0.0.1):
Not shown: 1660 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
25/tcp open smtp
53/tcp open domain
80/tcp open http
106/tcp open pop3pw
110/tcp open pop3
111/tcp open rpcbind
143/tcp open imap
443/tcp open https
465/tcp open smtps

Device type: general purpose

Running: Linux 2.4.X|2.5.X|2.6.X

OS details: Linux 2.5.25 - 2.6.3

Uptime 95 days

Nmap run completed -- 1 IP address (1 host up) scanned in 2.341 seconds

How to reset sshd config using WHM

2011-05-07T23:34:00.000+05:30

In somecases your ssh config may have corrupted or ssh port may have blocked in the server due to mistake. In such cases, you can reset the sshd_config from whm.
Login to your whm, then you need to access the URL given below in your browser. Remember to replace the $IPADDRESS with your IP address. This will reset the ssh port to 22.

http://$IPADDRESS:2086/scripts2/doautofixer?autofix=safesshrestart

Wrong mysql disk usage in cpanel.

2011-05-05T20:12:00.000+05:30

You have zero databases in your cpanel account. After login to your cpanel, you can see the mysql database consuming more disk space. This can be corrected by the following steps.

Login to server and edit cpanel.config.

[root@server /]# vi /var/cpanel/users/cpanel.config

Replace 'disk_usage_include_sqldbs=0' with 'disk_usage_include_sqldbs=1'

Save this file and run the command given below.

[root@server /]# /scripts/update_db_cache

In the whm-tweak setting, you need to enable the option
'Use INFORMATION_SCHEMA to acquire MySQL disk usage (MySQL 5+ required) '

/bin/mv: Argument list too long

2011-04-25T03:35:00.000+05:30

When you are trying to move large number of files such 200000 files. you can use the command

mv * /path/to/move

If you try the above command, you will be getting the error "/bin/mv: Argument list too long"

You can use the command given below to avoid this error ,

find /path/to/file -type f | xargs -i mv "{}" /path/to/move

Try this out.. :)

FFmpeg :: make: *** [ffmpeg_frame.lo] Error 1/

2011-04-19T03:41:00.000+05:30

Sometimes you will get the error given below when installing ffmpeg-php in your server.
FFmpeg :: make: *** [ffmpeg_frame.lo] Error 1

Fix:
modify the file ffmpeg_frame.c and replace every instance of PIX_FMT_RGBA32 with PIX_FMT_RGB32

Now run make and make install

Eg:

vi ffmpeg_frame.c
:%s/PIX_FMT_RGBA32/PIX_FMT_RGB32
:wq!

Another method is

cd /path/to/ffmpeg-php-0.6.0
cp -aP ffmpeg_frame.loT ffmpeg_frame.lo
make clean
./configure

How to install yasm

2011-04-19T00:19:00.000+05:30

You can follow the steps given below to install yasm from source.

# wget http://www.tortall.net/projects/yasm/releases/yasm-0.7.0.tar.gz

# tar zfvx yasm-0.7.0.tar.gz
# cd yasm-0.7.0
#  ./configure
# make 
# make install
You can check the yasm binary using the command
# which yasm
/usr/local/bin/yasm

How to install Yamdi

2011-04-19T00:13:00.000+05:30

You can follow the steps given below to install Yamdi

cd /usr/local/src/
wget http://downloads.sourceforge.net/project/yamdi/yamdi/1.4/yamdi-1.4.tar.gz?use_mirror=ufpr
tar zxf yamdi-1.4.tar.gz
cd yamdi-1.4
gcc yamdi.c -o yamdi -O2 -Wall
mv yamdi /usr/bin/
yamdi -h

You can check the yamdi binary using "which yamdi'

How to install qt-faststart with ffmpeg

2011-04-09T14:09:00.000+05:30

You can follow the steps given below to install qt-ffmpeg with ffmpeg. For this steps to work out, you should have a working ffmpeg installation in your server.

# svn checkout svn://svn.ffmpeg.org/ffmpeg/trunk ffmpeg
# cd ffmpeg
# ./configure
# make
#make tools/qt-faststart
#cp -a tools/qt-faststart /usr/bin/

Spool file is locked (another process is handling this message) : Unable to send emails ,exim

2011-04-04T17:45:00.001+05:30

There are many resons for this error. They may be due to dns, firewall.

Please try the fix given below.

#cd /var/spool/exim4/db
# mv * /backup
move all the files to a backup folder

#/etc/init.d/exim restart

This should fix the issue. If this doesnt fix the issue, please try by restarting the firewall. Firewall may be blocking your emails.

How to enable IP rotation in exim.

2011-04-04T16:08:00.002+05:30

If your server are having multiple IP and you want to send each emails in different IP address. You can follow the steps given below. This is used to maintain the ip reputation. While doing this, please make sure that this is not used for spamming.

Open you exim config,

vi /etc/exim.conf

search for the line : interface =

replace this line with
interface = 192.168.0.1${eval:${substr{-2}{1}{$tod_zulu}}%7+1}

If your server is having ip's from 192.168.0.11 to 192.168.0.20 , you can use above line.
+1 is is the starting ip ie 192.168.0.1'1'
%9 is the incriment value ie 11(192.168.0.11) to how much. here it is 20 (192.168.0.20)

Unable to load dynamic library ‘/usr/lib64/php/modules/ffmpeg.so

2011-03-28T04:54:00.000+05:30

if you are getting the error message “Unable to load dynamic library ‘/usr/lib64/php/modules/ffmpeg.so” when you add the ffmpeg.so extension to the PHP configuration file i.e. php.ini file and tries to run PHP.

PHP Warning: PHP Startup: Unable to load dynamic library ‘/usr/lib64/php/modules/ffmpeg.so’ – /usr/lib64/php/modules/ffmpeg.so: undefined symbol: _php_create_ffmpeg_frame in Unknown on line 0

Please try the fix given below.

Goto the the ffmpeg-php-0.x.0 directory and edit the ffmpeg_frame.c file

vi /usr/src/ffmpeg-php-0.6.0/ffmpeg_frame.c

Now replace every instance of ‘PIX_FMT_RGBA32′ with ‘PIX_FMT_RGB32′ in the file by executing

Save the file and recompile ffmpeg-php

#ldconfig
#phpize
#./configure --enable-shared --with-ffmpeg=/usr/local/cpffmpeg
#make -j$cpu
#make install

phpize : command not found

2011-03-28T02:59:00.000+05:30

#-bash: phpize: command not found

This error is due to "phpize" command not available on your server. To fix, install php-devel package.

yum install php-devel

How to install GIT

2011-03-28T02:16:00.000+05:30

Git is distributed version control system focused on speed, effectivity and real-world usability on large projects. Following are the steps to intsall Git

wget http://kernel.org/pub/software/scm/git/git-1.7.3.tar.bz2
tar jxvf git-1.7.3.tar.bz2
cd git-1.7.3
./configure
make && make install
git

Yum update failed.

2011-03-23T00:24:00.000+05:30

Yum update failed.
===================================
"-bash-3.1# yum update
Loading “installonlyn” plugin
error: no dbpath has been set
error: cannot open Packages database in /%{_dbpath}
Traceback (most recent call last):
File “/usr/bin/yum”, line 29, in ?
yummain.main(sys.argv[1:])
File “/usr/share/yum-cli/yummain.py”, line 82, in main
base.getOptionsConfig(args)
File “/usr/share/yum-cli/cli.py”, line 206, in getOptionsConfig
errorlevel=opts.errorlevel)
File “/usr/lib/python2.4/site-packages/yum/__init__.py”, line 132, in
doConfigSetup
self.conf = config.readMainConfig(startupconf)
File “/usr/lib/python2.4/site-packages/yum/config.py”, line 598, in
readMainConfig
yumvars['releasever'] = _getsysver(startupconf.installroot,
startupconf.distroverpkg)
File “/usr/lib/python2.4/site-packages/yum/config.py”, line 661, in
_getsysver
idx = ts.dbMatch(‘provides’, distroverpkg)
TypeError: rpmdb open failed"
==========================

If you are getting this error, you need to clear the database.

Yum clean all
rm -f /var/lib/rpm/_db*
rpm -rebuilddb
yum update

If this doesnt fix your issue, try the following steps also.

rm /dev/urandom
mknod -m 644 /dev/urandom c 1 9
yum clean all.

This should fix your issue.

Command to check the performance of the hard disk.

2011-03-21T03:50:00.002+05:30

Command to check the performance of the hard disk.

You can use the command given below to check the hard disk performance.

hdparm /dev/sda

/dev/sda:
multcount = 16 (on)
IO_support = 1 (32-bit)
readonly = 0 (off)
readahead = 256 (on)
geometry = 19457/255/63, sectors = 312581808, start = 0

You can replace /dev/sda with the name of your disk device.

Request exceeded the limit of 10 internal redirects due to probable configuration error. Use ‘LimitInternalRecursion’ to increase the limit ifnecessary. Use ‘LogLevel debug’ to get a backtrace

2011-03-20T05:19:00.001+05:30

Request exceeded the limit of 10 internal redirects due to probable configuration error. Use ‘LimitInternalRecursion’ to increase the limit ifnecessary. Use ‘LogLevel debug’ to get a backtrace

When you try to browse your website, if you are getting this error. This means that you have exceeded the limit of intername redictions used in your website.

To avoid this error message simply use following code in .htaccess file.

RewriteRule .* - [L]

Linux Plesk Back end files.

2011-01-22T20:37:00.000+05:30

Plesk root directory : /usr/local/psa
Plesk version          : /usr/local/psa/version
Plesk Admin pass    : /etc/psa/.psa.shadow
Plesk conf file         : /etc/psa/psa.conf
Apache conf           : /etc/httpd/conf/httpd.conf
Plesk apache startup script : /usr/local/psa/admin/bin/httpsdctl start
Apache log files      : /var/log/http/
Php conf                : /etc/php.ini
Named conf           : /var/named/run-root/etc/named.conf
Named db              : /var/named/run-root/var/domainname
Log                       : /var/log/messages
Names restart         : /etc/init.d/named restart
Mysql Db location : /var/lib/mysql
Mysql conf            : /etc/my.cnf
Mysql log              : /var/log/mysql.log
Plesk qmail            : /var/qmail
Mail Dir for domain: /var/qmail/mailnames/domainname
Maillog                  : /var/log/maillog
Plesk home dir       : /var/www/vhosts/domain.com
Plesk Doc root       : /var/www/vhost/domainname/httpdocs
Subdomain Docroot: /var/www/vhost/domainname/subdomain
Domain specific log: /var/www/vhosts/domainname/statistics/logs

Plesk Db:
Plesk database is called psa. Admin logins are used to access psa db.

Following are the tables in psa db
1. Domains

2. Clients
3. db_users
4. db_bases
5. disk_spaces
6. mail
7. lockout
8. web_users

Move worpress site from subfolder to root

2011-01-14T04:31:00.000+05:30

Assume that wordpress is installed in /blog folder and root domain is abhionlinux.co.cc
You can follow the steps below to move the blog to root dir.

1. Backup the folder /blog , this is done as a precaution.
2. Copy all the files in blog to root dir, make sure .htaccess file is also copied. There shouldnt be any index files such as index.php or index.html.
3. Add the following line in wp-config.php under root dir.

define('RELOCATE',true);

4. Open the URL abhionlinux.co.cc/wp-login.php and enter the admin login details.

5. Go to general settings, Make sure  in wordpress address field  you have abhionlinux.co.cc(root dir) and make blog address URL as abhionlinux.co.cc(root dir). Most likely it will be having

http://abhionlinux.co.cc/blog, dont leave '/' in domain name.

6. Check htaccess in root dir and make sure it is similar to the one given below.

====================

IfModule mod_rewrite.c
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
IfModule
===================


Now your wordpress site is move from subfolder to root dir. 
7. You can remove the line below from the file wp-config.php

define('RELOCATE',true);

Try it out !!!

Moodle : ERROR: Could not find or create a directory (/home/username/public_html/uploaddata/16)

2011-01-13T01:50:00.000+05:30

After creating the course, when you try to add files/folders in the course you will get an error "ERROR: Could not find or create a directory (/home/username/public_html/uploaddata/16"

This is due permission/ownership issue/.
Make sure that all your files and folders are having correct ownership (username.username)
Check the permission for /uploaddata/, this should be set to 777.

Unable to login to Moodle site "Your session has timed out. Please login again"

2011-01-13T01:47:00.000+05:30

When you try to login to your Moodle admin section, you will get an error showing "Your session has timed out. Please login again"

Fix:
Check whether the folder /uploaddata/sessions/ is having 777 permission.
Clear all the session files in this folder.

Then you will be able to login to your website.

PGsql database not showing in cpanel

2010-12-23T03:24:00.002+05:30

Go to /var/lib/pgsql/data/pg_hba.conf
Change ‘md5′ to ‘trust’.
It should look like :

local all all trust
host all all 127.0.0.1 255.255.255.255 trust

Error while installin Xdebug pecl module

2010-10-22T03:22:00.002+05:30

[root@server ~]#pecl install xdebug

downloading xdebug-2.0.3.tgz …
Starting to download xdebug-2.0.3.tgz (286,325 bytes)
……………………………….done: 286,325 bytes
66 source files, building
running: phpize
Configuring for:
PHP Api Version: 20041225
Zend Module Api No: 20060613
Zend Extension Api No: 220060519
building in /var/tmp/pear-build-root/xdebug-2.0.3
running: /root/tmp/pear/cache/xdebug-2.0.3/configure
checking for egrep… grep -E
checking for a sed that does not truncate output… /bin/sed
checking for gcc… gcc
checking for C compiler default output file name… a.out
checking whether the C compiler works… configure: error: cannot run C compiled programs.
If you meant to cross compile, use `–host’.
See `config.log’ for more details.
ERROR: `/root/tmp/pear/cache/xdebug-2.0.3/configure’ failed

FIX:
Execute the commands:-

[root@server ~]#cd /var/tmp/
[root@server ~]#rm -fr pear pear-build-root
[root@server ~]#ln -s /root/tmp/pear-build-root .
[root@server ~]#mkdir -p /root/tmp/pear/download

Try to install the package now:-

[root@server ~]#pecl install xdebug

It will be installed correctly in the server.

Change exim interface IP address

2010-10-20T06:22:00.000+05:30

We can change the exim interface IP by editing exim.conf.

1. Open exim.conf in the text editor.

vi /etc/exim.conf

2. Check for the following lines in exim.conf
======================
remote_smtp:

driver = smtp

interface=
======================
You need to modify this as given below

*******************
remote_smtp:

driver = smtp

interface=xx.xx.xx.xx

Where xx.xx.xx.xx with your IP address.
******************

3. You need to restart exim service in the server.

/etc/init.d/exim restart

How to upload multiple files using ftp in command line mode.

2010-10-15T19:38:00.000+05:30

You can use lftp command to upload multiple files

lftp hostname

> user ftpusername ftppassword
> mirror source destination [to download entire directory]
> mirror -R source destination [to upload entire directory]

Uploading Error in WordPress. “Unable to create directory-Is its parent directory writable by the server?"

2010-10-15T19:17:00.001+05:30

While uploading files such as plugins and themes, we will get an error “Unable to create directory /home/username/public_html/wp-content/uploads/2010/10. Is its parent directory writable by the server?”

This is due to changes in server, host or upgrading to new version

Firstly, we need to check the upload file path.

1. Login to wp-admin
2. Click on setting --> media --> "Store upload in this folder"
It will be like /home/username/public_html/wp-content/uploads , change it to wp-contents/upload.

This will fix you issue. If this doesnt fix the issue, you need to check the folder permission. Change the permission of wp-content and uploads to 777 and correct ownership of all the files/folders.

how to set time zone in VPS node (OpenVZ)

2010-10-03T18:33:00.000+05:30

Below is the steps to set the time zone for a particular node in VPS.

1. Login to the main node.(SSH).
2. Stop the node(container) which you want to set time.
   # vzctl stop 777
            777 = Container ID
3.Set the container to have capability to change the time zone.
   # vzctl set 777 --capability sys_time:on --save

4. Start the container and login to it.
   # vzctl start 777
   # vzctl enter 777
5. Change your local timezone.
   # mv /etc/localtime /etc/localtime_bk
   # ln -s /usr/share/zoneinfo/America/Chicago /etc/localtime
6. Set the date
   # date 100318312010
time has been set to 18.31 on 3rd Oct 2010
(10-Month, 03-Day, 06-Hours, 31-Minutes, 2010 -Year

Phpmotion : Uploading video asks .pl-File to download

2010-09-25T07:53:00.000+05:30

When we try to upload videos in to phpmotion, it will be asking to download uu_upload.pl.

If you are getting the download an upload script fo video, it means that your site is not executing the script but it is treating as plain text type doc. what we have to do is to make your site to run .pl and .cgi files.

For this, you need to check the permission of cgi-bin folder and files inside it,. it should be 755.

To make your cgi and pl files to be run in your site, you need to add the following lines in your htaccess.

===============================

AddHandler cgi-script .cgi .pl
Options +ExecCGI Options +ExecCGI

===============================

http://phpmotion.com/forum/index.php?topic=3539.0

Phpmotion : Uploading video asks .pl-File to download

2010-09-25T07:43:00.000+05:30

When we try to upload videos in to phpmotion, it will be asking to download uu_upload.pl.

For this, you need to check the permission of cgi-bin folder and files inside it,. it should be 755.

To make your cgi and pl files to be run in your site, you need to add the following lines in your htaccess.

===============================

AddHandler cgi-script .cgi .pl

Options +ExecCGI

Options +ExecCGI

===============================

word-press url change, site not loading correctly

2010-07-01T15:10:00.000+05:30

If you wordpress url has changed, while accessing the domain. Your site will not load correctly.
For this you need to change the values in the wordpress database.

First you need to change the siteurl field inthe wp_otions table,

select * from wp_option where option_name="siteurl";

update wp_options SET option_value="http://newdomainname.com" where option_name="siteurl"

Then you need to update the "home" field in the wp_otions table,
select * from wp_options where option_name="home";
update wp_options SET option_value="http://newdomainname.com" where option_name="home";

Queueprocd Failed.

2010-07-01T14:46:00.000+05:30

Usually you need to check perlmodules installed in the server /scripts/checkperlmodules
Then /scripts/upcp should fix the issue.

If this does not fix the issue, it may be issue with the perl.
Check whether there are two perl binaries in the server.

For eg :

/usr/bin/perl
/usr/local/bin/perl

Solution :
You need to remove /usr/bin/perl, and created a symlink for it to /usr/local/bin/perl via:
ln -s /usr/local/bin/perl /usr/bin/perl

This is the proper setup to allow for Perl to function properly with cPanel. Once this was fixed, You need to run the following command:

/scripts/checkperlmodules --full
Upon testing, you can see all Perl modules are now properly installed, and Queueprocd is up well.

How to check the server is Suexec

2010-06-29T14:26:00.000+05:30

Login into you server with the root login details and run following command

[root@server]# /usr/local/cpanel/bin/rebuild_phpconf --current

If server is Suexec then result would look like

DEFAULT PHP: 5
PHP4 SAPI: suphp
PHP5 SAPI: suphp
SUEXEC: enabled

If you are not sure about Shell then you can also check the SuExec is enabled or not? from your WHM.Lgin into your WHM and in the menu find Configure PHP and SuExec

Check the drop down box for "PHP 4/5 Handler" - and if beside that it says "suPHP" - Then your sever is SuExec enabled

If you are not having server root login details or WHM access.Then you can create a php file udner your account from cPanel >> File Manager and change the permissions on that file to 777 and open it in a browser. If it gives 500 Internal Server Error, your most probably running suPHP.

As well as you can also create the phpinfo page under your account from your cPanel >> File manager For ex. phpinfo.php with the following code

After creating phpinfo.php page browse it http://yourdomainname.com/phpinfo.php and if it shows

Server API = Apache then server is not running PHP in Suexec mode

And if

Server API = CGI the server is running PHP in Suexec mode

limit number of connection to a server using IPTABLES

2010-06-09T13:13:00.000+05:30

We can limit number of connections to the server using the command below.

iptables -I INPUT -p tcp --syn --dport 22 -m connlimit --conlimit-above 2 -j REJECT

service iptables save

service iptables restart

How to increase maximum execution time using htaccess

2010-06-08T11:10:00.002+05:30

You can change the maximum execution time value using the following

php_value max_execution_time 2000

OpenSSH Public Key Authentication

2010-06-05T16:31:00.000+05:30

Public-key authentication is based on the use of digital signatures. Each user creates a pair of 'key' files. One of these key files is the user's public key, and the other is the user's private key. The server knows the user's public key, and only the user has the private key.

When the user tries to authenticate herself, the server checks for matching public keys and sends a challenge to the user end. The user is authenticated by signing the challenge using her private key.
Remember that your private key file is used to authenticate you. Never expose your private keys. If anyone else can access your private key file, they can attempt to login to the remote host computer as you, and claim to be you. Therefore it is extremely important that you keep your private key file in a secure place and make sure that no one else has access to it.

Public-key authentication is is based on the use of digital signatures. Each users have to create a pair of keys. ie public key and private key. Private key is owned by user and the public key is given to the server. When the user tries to authenticate, server check for the matching public key and sends a challenge to the user. Private key is used to authenticate the user, so never provide your private keys to others. If anyone got your private key, they can login to the server as you. So keep your private key file in a secure place and make sure that no one else has access to it.
Secure Shell (SSH) public key authentication is used for clients to acess servers without using passwords.

Steps to configure public key.
OpenSSH is the SSH software installed on the client system. The ssh -V will show the openssh details in the server.

$ ssh -V
OpenSSH_3.6.1p1+CAN-2003-0693, SSH protocols 1.5/2.0, OpenSSL 0x0090702f

If ssh is running on a non standard port, you need to put the custom port. You can provide the custom port as follows.

$ ssh -p 1111 server.test.com
or
$ ssh -oPort=1111 server.test.com

RSA key pair will be generated in the client system.Public key will be provided to the server that is to be connnected, while the private key should remain in the secured area in the client system.By default it will be in ~/.ssh/id_rsa
New keys can be generated using the command ssh-keygen

client$ mkdir ~/.ssh
client$ chmod 700 ~/.ssh
client$ ssh-keygen -t rsa
Enter passphrase
Enter same passphrase again:

File permissions should be protected to prevent other users from being able to read the key pairs.OpenSSH may refuse to support public key authentication if the file permissions are too open.

$ chmod -R 700 ~/.ssh

Public key must be copied to any servers that will be accesses by the client.Public key information to be copied should be located in the ~/.ssh/id_rsa.pub file on the client. Public key data must be appended into ~/.ssh/authorized_keys file on the servers.

First upload public key from client to server

Client$ scp ~/.ssh/id_rsa.pub root@server.test.com

Setup the public key in the server

server$ mkdir ~/.ssh
erver$ chmod 700 ~/.ssh
server$ cat ~/id_rsa.pub >> ~/.ssh/authorized_keys
server$ chmod 600 ~/.ssh/authorized_keys

We should always append new public key data to the authorized_keys file, as multiple public keys may be in use. Each public key entry must be on a different line

"from" statement can be used before public key entries in the ~/.ssh/authorized_keys file on the servers to limit where the client system is permitted to access the server from. Without a from limit, any client will the appropriate private key data will be able to connect to the server from anywhere. Key pair should only work, if the client connecting to the server is from a host under test.com, set from="*.test.com" before the public key data.

server$ cat ~/.ssh/authorized_keys
from="*.test.com" ssh-rsa AAAAB3NzaC1

Multiple hosts or addresses can be specified as comma separated values.
from="*.test.com,,external.example.com"

Video uploading throws error -- Failed to find flength file.

2010-05-29T16:44:00.002+05:30

This is a well known error with the uploader component (which is commonly used by many scripts like clipshare, phpmotion etc). This is just a cosmetic error and nothing to do with the real uploading process. The best "workaround" for this issue is to disable the error message. To do so, locate the file cgi-bin/uu_ini_status.pl inside your script folder and change the value of my $flength_file_exists from 0 to 1.

The bad news is, you won't see the upload status counter. The good news is, your upload process will work just fine!

PhpMotion Installation

2010-05-28T19:43:00.000+05:30

If you want to run PHPmotion you will need either to have a dedicated server with the following required modules installed OR a web hosting provider that already has these features.

Servers - Linux/Unix server

PHP 4.3 and above (including support of CLI)
MySQL database server
LAME MP3 Encoder
Libogg + Libvorbis
Mencoder and also Mplayer
FFMpeg-PHP
GD Library 2 or higher
CGI-BIN

PHP Settings

open_basedir = (no value)
upload_max_filesize = 100M
post_max_size = 100M
max_execution_time = 1500
session.gc_maxlifetime = 14000
safe_mode = off
enable_dl = On

Apache Web Server

.htaccess support
mod rewrite

You will need to have your Mysql Database Information. You can create a Mysql database via your web hosts control panel
- Mysql Database Name
- Mysql Database User Name
- Mysql Database Password

Downloading PHPmotion

You can download phpmotion from the URL
http://phpmotion.com/content/view/1/180/

General Instructions

Unzip the download file
Upload (the contents) to your website using FTP
The following files MUST be uploaded in Binary mode
- /phpshiled/all files in this folder
- /classes/config.php
- /addons/customprofile/pimp.class.php
- /addons/customprofile/index.php
The following files must be CHMOD to 755
- /cgi-bin/all files and folder in this folder
Start the installation wizard by (opening in your broswer) http://www.yourdomain.com/setup (you will be required to chmod a few more files by the setup wizard)

The setup wizard will guide you through the rest of the installation process.

Additional Instructions

Installing to a Sub-Directory

If you are installing to a sub directory (example: http://www.yourdomain.com/**phpmotion**) you should do all the steps above and also the steps below additional steps

Edit the following files to include your subfolder name: (in this example the subfolder name we have inserted is phpmotion )

/cgi-bin/uu_default_config.pm
/cgi-bin/audio/uu_default_config.pm

    temp_dir                  => $ENV{'DOCUMENT_ROOT'} . '/phpmotion/temp/',
    upload_dir               => $ENV{'DOCUMENT_ROOT'} . '/phpmotion/uploads/avi/',
    redirect_url             => '/phpmotion/uploader_finished.php',
    path_to_upload           => '/phpmotion/uploads/avi/',

/audio_uploader_conlib.php
/uploader_conlib.php

$path_to_upload_script      = '/phpmotion/cgi-bin/uu_upload.pl';
 $path_to_ini_status_script  = '/phpmotion/cgi-bin/uu_ini_status.pl';

/.htaccess

#----- if phpmotion is installed in a sub directory edit the RewriteBase as follows -----#
  # EXAMPLE => RewriteBase /phpmotion
  # EXAMPLE => RewriteBase /phpmotion
  RewriteBase /

For trouble sooting common errors in phpmotion,

http://wiki.phpmotion.com/CommonInstallationErrors

Clipbucket Video error : "This video might not work properly "

2010-05-21T10:39:00.000+05:30

When we try to play the upoaded video in clipbucket, we will get the error "This video might not work properly " in the top of the video. This is becuase, server is unable to convert that video. To solve this issue, we need to add a cron under the user to convert the video and should verify the converted video.

vi /var/spool/cron/abhilash
* * * * * php -q /relative/path/to/clipbucket/actions/video_convert.php
* * * * * php -q /relative/path/to/clipbucket/actions/verify_converted_videos.php

Then restart the cron /etc/init.d/crond restart

For any further clarification of clipbucket installation you can refer the link:
http://docs.clip-bucket.com/clipbucket-docs/clipbucket-installation

RVSkin installation in cpanel server

2010-05-17T10:20:00.000+05:30

SSH as root to server that was registered while purchasing the license and run:
mkdir /root/rvadmin
cd /root/rvadmin
wget http://download.rvglobalsoft.com/download.php/download/rvskin-auto/saveto/rvauto.tar.bz2
bunzip2 -d rvauto.tar.bz2
tar -xvf rvauto.tar
perl /root/rvadmin/auto_rvskin.pl

Answer a couple of questions on your shell, and wait until it finishes. First installation will take 2- 5 minutes to install. Installer will create a new hosting account 'rvadmin'. Don't terminate it. It will be used for internal RVSkin configuration management.

Log in to RVSkin Manager. Both root and reseller are able to access RVSkin Manager in WHM / Plugins (at the bottom left menu). If you cannot find the RVSkin Manager menu, please close WHM and open it again
If there is no messages display on the skin, please run this command on your SSH.

rm -f /usr/local/cpanel/Cpanel/rvversion
perl /root/rvadmin/auto_rvskin.pl

In RVSkin Manager:

Set global configuration
Set default language
Create default feature list for user and for reseller
Set tweak setting, reseller feature control, body links, top links, help, tutorial links, and etc.
Test configuration setting in 2 hosting accounts.
- rvadmin: this account can consider to be account belong to root
- reseller's client: this account will reflect setting from reseller skin manager. If it is not configured, it will remain anonymous.
If you are having any issues in installing rvskin
http://www.rvskin.com/index.php?page=public/installation_troubleshooting

Send/Recieve email using Telnet

2010-05-12T22:20:00.001+05:30

Send mail through SMTP using Telnet

Telnet to the server via port 25.

1. Type “EHLO example.com” and hit enter.

2. “MAIL FROM: sender@domain.com” and hit enter.

3. “RCPT TO: recipient@domain.com” and hit enter.

4. “DATA” and hit enter.

5. Type your message body and hit enter.

6. Key in ” . ” and press enter to exit.

You will recieve the mail.

==============================================
Example:

root@test.com]# telnet 192.168.0.25 25
Trying 192.168.0.25...
Connected to 192.168.0.25 (192.168.0.25).
Escape character is '^]'.
220 test.tt.example.com ESMTP MAIL Service, Version: 5.0.2195.6713 ready at Thu, 3 Apr 2008 15:39:17 +0800
EHLO Vsource.com
250-smtp11.klk.example.com Hello [192.168.0.192]
250-AUTH GSSAPI NTLM LOGIN
250-AUTH=LOGIN
250-TURN
250-ATRN
250-SIZE
250-ETRN
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-8bitmime
250-BINARYMIME
250-CHUNKING
250-VRFY
250 OK
MAIL FROM: abhi@example.com
250 2.1.0 abhi@example.com....Sender OK
RCPT TO: abhi_tt@example.com
250 2.1.5 abhi_tt@example.com
DATA
354 Start mail input; end with .
this is a test over SMTP
.
250 2.6.0 Queued mail for delivery
quit
221 2.0.0 smtp11.klk.example.com Service closing transmission channel
Connection closed by foreign host.
[root@test.com]#

How to set multiple IP addresses using Linux command line

2010-04-21T00:48:00.000+05:30

Go to /etc/sysconfig/network-scripts
Make multiple copies of ifcfg-eth0 and name them as ifcfg-eth0:0, ifcfg-eth0:1 etc.
Open each of them and at least change the IPADDR to your chosen IP address and the NETMASK to the subnet mask for that IP address.
A sample entry would look like this:


DEVICE=eth0:0
BOOTPROTO=static
IPADDR=34.123.111.21
NETMASK=255.255.255.0
ONBOOT=yes

Restart the network:
/sbin/service network restart
/etc/init.d/ipaliases restart (for cpanel servers)

If you have more than 100's of IP, it is difficult to choose above method. For that you can try the following method.

[root@server ~]#d /etc/sysconfig/network-scripts/ – this is where the network settings are being searched for
[root@server network-scripts]# vi ifcfg-eth0-range0 – this will be the file where we define the new IP class(considering that our main interface is called eth0)
Add this content to the file:

IPADDR_START=192.168.0.1
IPADDR_END=

192.168.0.

.28
CLONENUM_START=1
NETMASK=255.255.255.240

Explanation:
IPADDR_START – the first IP of the class you want to add
IPADDR_END – last IP of the class you want to add
CLONENUM_START – the number with which the virtual interface will start, this will create the virtual interfaces eth0:1 to eth0:28.
If you have more classes that you want to add on the next class CLONENUM will start at 29.
NETMASK – the mask for the IP class
After all this was added to the file and edited accordingly just save and restart the network.

.

Install and Configure Cacti Network Graphing Tool

2010-04-20T17:59:00.000+05:30

Cacti is a complete frontend to RRDTool, it stores all of the necessary information to create graphs and populate them with data in a MySQL database. The frontend is completely PHP driven. Along with being able to maintain Graphs, Data Sources, and Round Robin Archives in a database, cacti handles the data gathering. There is also SNMP support for those used to creating traffic graphs with MRTG.

Required software(s)

You need to install the following software on RHEL / Fedora / CentOS Linux:

MySQL Server : Store cacti data.
NET-SNMP server - SNMP (Simple Network Management Protocol) is a protocol used for network management.
PHP with net-snmp module - Access SNMP data using PHP.
Apache / lighttpd / ngnix webserver : Web server to display graphs created with PHP and RRDTOOL

First, login as root user and type the following command to install mysql, apache and php

# yum install mysql-server mysql php-mysql php-pear php-common  php-gd php-devel php php-mbstring php-cli php-snmp php-pear-Net-SMTP  php-mysql httpd

Configure MySQL server

First, set root password:
# mysqladmin -u root password NEWPASSWORD

Create cacti MySQL database
Create a database called cacti, enter:
# mysql -u root -p -e 'create database cacti'

Create a user called cacti with a password called zYn95ph43zYtq, enter:
# mysql -u root -p

mysql> GRANT ALL ON cacti.* TO cacti@localhost IDENTIFIED BY 'zYn95ph43zYtq';
mysql> FLUSH privileges;
mysql> \q

Install snmpd

Type the following command to install net-snmpd
# yum install net-snmp-utils php-snmp net-snmp-libs
Configure snmpd, open /etc/snmp/snmpd.conf
# vi /etc/snmp/snmpd.conf

Append / modify it as follows (see snmpd.conf man page for details):

com2sec local     localhost           public
group MyRWGroup v1         local
group MyRWGroup v2c        local
group MyRWGroup usm        local
view all    included  .1                               80
access MyRWGroup ""      any       noauth    exact  all    all    none
syslocation Unknown (edit /etc/snmp/snmpd.conf)
syscontact Root  (configure /etc/snmp/snmp.local.conf)
pass .1.3.6.1.4.1.4413.4.1 /usr/bin/ucd5820stat

Save and close the file. Turn on snmpd service:

# /etc/init.d/snmpd start
# chkconfig snmpd on

Make sure you are getting information from snmpd:
# snmpwalk -v 1 -c public localhost IP-MIB::ipAdEntIfIndex
Sample ouptut:

IP-MIB::ipAdEntIfIndex.10.10.29.68 = INTEGER: 2
IP-MIB::ipAdEntIfIndex.67.yy.zz.eee = INTEGER: 3
IP-MIB::ipAdEntIfIndex.127.0.0.1 = INTEGER: 1

Install cacti

First, make sure EPEL repo is enabled. Type the following command to install cacti:
# yum install cacti

To install EPEL repo
http://www.cyberciti.biz/faq/rhel-fedora-centos-linux-enable-epel-repo/

Install cacti tables

Type the following command to find out cacti.sql path:
# rpm -ql cacti | grep cacti.sql
Sample output:

/usr/share/doc/cacti-0.8.7d/cacti.sql

Type the following command to install cacti tables (you need to type the cacti user password):
# mysql -u cacti -p cacti < /usr/share/doc/cacti-0.8.7d/cacti.sql

Configure cacti

Open /etc/cacti/db.php file, enter:
# vi /etc/cacti/db.php
Make changes as follows:

 
/* make sure these values refect your actual database/host/user/password */
$database_type = "mysql";
$database_default = "cacti";
$database_hostname = "localhost";
$database_username = "cacti";
$database_password = "zYn95ph43zYtq";
$database_port = "3306";

Save and close the file.

Configure httpd

Open /etc/httpd/conf.d/cacti.conf file, enter:
# vi /etc/httpd/conf.d/cacti.conf

You need to update allow from line. Either set to ALL or your LAN subnet to allow access to cacti:

 
#
# Cacti: An rrd based graphing tool
#
Alias /cacti    /usr/share/cacti
 

        Order Deny,Allow
        Deny from all
        Allow from 10.0.0.0/8

Another option is create /usr/share/cacti/.htaccess file and password protect the directory. Finally, restart httpd:
# service httpd restart

Setup cacti cronjob

Open /etc/cron.d/cacti file, enter:
# vi /etc/cron.d/cacti
Uncomment the line:

*/5 * * * *     cacti   /usr/bin/php /usr/share/cacti/poller.php > /dev/null 2>&1

Save and close the file.

Run cacti installer

Now cacti is ready to install. Fire a webbrowser and type the url:
http://your.example.com/cacti/
OR
http://your.server.ip.address/cacti/

The default username and password for cacti is admin / admin. Upon first login, you will be force to change the default password.

.

Semaphore issue - Unable to start apache.

2010-04-10T12:52:00.004+05:30

Semaphores are used for communicating between the active processes of a certain application. In the case of Apache, they're used to communicate between the parent and child processes. If Apache can't write these things down, then it can't communicate properly with all of the processes it starts.
I'd assume if you're reading this article, Apache has stopped running. Run this command as root
# ipcs -s

If you see a list of semaphores, Apache has not cleaned up after itself, and some semaphores are stuck. Clear them out with this command:
# for i in `ipcs -s | awk '/httpd/ {print $2}'`; do (ipcrm -s $i); done

Now, in almost all cases, Apache should start properly.  If it doesn't, 
you may just be completely out of available semaphores.  You may want to
 increase your available semaphores, and you'll need to tickle your 
kernel to do so.  Add this to /etc/sysctl.conf:

kernel.msgmni = 1024
kernel.sem = 250 256000 32 1024
And then run sysctl -p to pick up the new changes.

how to know the OS version in linux

2010-04-08T14:52:00.002+05:30

uname -a
cat /proc/version
cat /etc/issue

/etc/redhat-release
/etc/debian_version
/etc/SuSE-release
/etc/slackware-version
/etc/gentoo-release

Compilation of apache and php

2010-03-27T19:32:00.000+05:30

Apache 2 source distribution available from http://www.apache.org.
PHP source distribution available from http://www.php.net/.
For the compilation make and gcc must be installed in the server. If it is not installed you can download it and install from ftp://mirrors.kernel.org/gnu/

Before starting to compile Apache and PHP you must uninstall all previous Apache and PHP related RPMs installed on your system. To uninstall these packages you can use Red Hat Package Manager (rpm) utility. If you are using X Windows you can also use GUI utilities like gnorpm and kpackge, if installed, to uninstall these RPMs.

Compiling Apache

Using shell, (or open a new virtual console window if working in X Windows) change to directory where you have downloaded Apache 2 source. In my case it is /usr/src.

$ cd /usr/src
$ gunzip httpd-2.0.44.tar.gz or gzip -d httpd-2.0.44.tar.gz
$ tar -zxvf httpd-2.0.44.tar.gz
$ cd /usr/src/httpd-2.0.44
Now we have to configure apache for compilation.

./configure --help

$ ./configure --prefix=/wwwroot --enable-so

First option --prefix tells configure script that we want Apache to be installed in directory /wwwroot. If we don't provide a prefix option than it'll be installed in default location, which is /usr/local/apache2.

I am installing everything in /wwwroot because:

   1. when a new version of PHP and Apache is released, I only have to rename /wwwroot directory to some other name like /wwwrootold and then I can install new versions in /wwwroot directory again. If new installation works properly then I can simply copy configuration files from old directory to /wwwroot.

   2. users new to compiling software from source, after compiling and installing it, try to find a way to uninstall the software. So, benefit of keeping everything at one place is; if someone wants to uninstall Apache and PHP then he just has to delete /wwwroot directory (After stopping Apache, if it is running).

Second option --enable-so tells configure to enable module so, which allows Apache to load shared modules. We need this option because we are compiling PHP as Apache shared module.

Example Apache configure command line looks like this. After configure finishes we have to compile Apache.
make

To compile Apache a utility called make is used. make reads a file named Makefile in the source directory. In the Makefile step by step instructions are written about how to compile the software. Benefit of using make is that if some of the source files are changed and we compile software again, then only files which are changed and files which depend on changed files are recompiled.

To compile Apache source we have to issue this command in the Apache source directory (/usr/src/httpd-2.0.44):

$ make

When you type make It will start compiling Apache. It will take several minutes depending upon the speed of your computer. After make finishes, shell prompt is available. Now source has been compiled. We will use make install command to install Apache

$ make install

This will install Apache to /wwwroot directory. Now test your Apache installation by starting Apache:

$ /wwwroot/bin/apachectl start

If you are returned to shell prompt and no error etc. is displayed then Apache is started.

Now you can open a web browser like lynx and visit Apache homepage:

$ lynx http://localhost

It'll show Apache homepage, where you can read Apache documentation to know more about Apache.

To stop Apache you can use:

$ /wwwroot/bin/apachectl stop

Compiling PHP

Change to directory where you have downloaded PHP source.

$ cd /usr/src

Then we have to extract PHP source files from php-4.3.0.tar.gz file.

To decompress the compressed file use:

$ gunzip php-4.3.0.tar.gz

You will have a file named php-4.3.0.tar in your current directory. Now to extract its contents use:

$ tar -xvf php-4.3.0.tar

Both above steps can be completed by using this command:
$ tar -zxvf php-4.3.0.tar.gz

A new directory php-4.3.0 will be created in your current directory. For me its /usr/src/php-4.3.0.

Now change to this directory:

$ cd /usr/src/php-4.3.0

Now we have to configure PHP for compilation process. There are hundreds of options which can be provided to configure script. These options include the option to specify where PHP should be installed, which functionality should be enabled, like functionality to access mysql databases from PHP and which extensions have to be compiled etc. To see a list of options supported by PHP configure, type:

$ ./configure --help

It'll show a list of all options supported by the version of PHP that you are using.

Extensions provide additional functionality which core PHP doesn't provide. For example to create images --with-gd option can be used. But for these extensions to work, appropriate libraries must have been installed. If you use some --with option and that library isn't installed on your system then configure will fail. So, my advice is, for the first time don't try to use any extension.

To compile PHP as Apache shared module we have to provide path to apache apxs utility, which in our case was installed in /wwwroot/bin/ when we installed Apache. So, in PHP source directory (/usr/src/php-4.3.0) execute this command :

$ ./configure --prefix=/wwwroot/php --with-apxs2=/wwwroot/bin/apxs --with-config-file-path=/wwwroot/php --with-mysql

First option --prefix=/wwwroot/php tells configure script that we want PHP to be installed in /wwwroot/php directory. Otherwise it'll be installed in some default location (/usr/local).

Second option --with-apxs2 specifies that we want to install PHP as Apache 2 shared module.

Third option --with-config-file-path specifies that PHP should look for php.ini file in /wwwroot/php directory. Php.ini file contains various settings, which can be used to configure PHP after it has been installed. Settings like path to directory where php extensions are installed. Options like max_execution_time in php.ini specifies maximum time a script is allowed to run before it is terminated by PHP parser.

    {Note} You don't have to specify name of the php.ini file when using --with-config-file-path option. Only directory path where php.ini file will be stored has to be specified. So, don't use --with-config-file-path=/wwwroot/php/php.ini, but instead use --with-config-file-path=/wwwroot/php.

Fourth option --with-mysql enables support to access mysql databases through PHP. After --with-mysql we can optionally specify directory where mysql is installed like --with-mysql=/usr/local/mysql. To use mysql database functions you must have mysql database installed on your system. If you don't have mysql installed you can remove this option. If this option is not used then library, which is bundled with PHP is used to access mysql databases.

After configure finishes. You have to type make to compile PHP:

$ make

It will take several minutes to compile. After make finishes and, no error etc. is displayed then PHP has been compiled successfully. If any warning is displayed then, normally, you can ignore it.

After this, if Apache is running stop Apache:

$ /wwwroot/bin/apachectl stop

Now you can execute make install from within PHP source directory to install PHP to /wwwroot/php directory:

$ make install

make install will install PHP4 module to Apache's modules sub-directory (/wwwroot/modules) and add a line like this:

LoadModule php4_module modules/libphp4.so

to apache configuration file (/wwwroot/conf/httpd.conf). This line allows Apache to automatically load PHP module when Apache starts. If this line is not added by PHP install, which in my case wasn't, then you can add it yourself. To add this line yourself, search for a word LoadModule in /wwwroot/conf/httpd.conf file. This word will be somewhere under section "Dynamic Shared Object (DSO) Support". Under this section, on a new line, add the above line.

Now you have to add another line to this httpd.conf file so that Apache invokes PHP parser whenever a file with extension php (.php) is accessed. When PHP parser is invoked by Apache it reads .php file which contains PHP code blocks, html tags and other text. Parser then executes PHP code found inside blocks and then merges PHP code results and other html content (as is). Resulting output is then sent back to Apache which in turn sends it to web browser which requested the file.

The line to be added is:

AddType application/x-httpd-php .php

To add this line search for word AddType in httpd.conf file. There will be a line like this:

AddType application/x-tar .tgz

Below this line add (on a new line):

AddType application/x-httpd-php .php

You can add any file extension in addition to .php if you want to invoke PHP parser for any other file extension also. Like:

AddType application/x-httpd-php .phtml

will invoke PHP parser whenever any file with phtml extension (.phtml) is accessed.

Save this file and then start Apache:

$ /wwwroot/bin/apachectl start

Enabling some PHP extensions:

You can get list of core configure options supported by PHP see http://www.php.net/manual/en/configure.php.

For example if you want to create images using PHP, you first need to install gd library using RPMs or by compiling from source. Then you can use --with-gd option to enable gd support from PHP like this:

$ ./configure --prefix=/wwwroot/php --with-apxs2=/wwwroot/bin/apxs --with-config-file-path=/wwwroot/php --with-gd

    {Note} GD depends on some other libraries to create images in different formats. So, some other libraries like png, jpeg , zlib also have to be installed.

.

Unable to upload large files via ftp

2010-03-25T21:51:00.002+05:30

Add the following lines to lines to /etc/proftpd.conf

================
AllowRetrieveRestart on
AllowOverwrite on
AllowStoreRestart on
================

Restart ftp and this should fix the issue.

.

Linux Server Security

2010-03-18T11:51:00.001+05:30

Following are the steps for securing cpanel servers:

1. Sysctl Hardening
http://www.eth0.us/sysctl

2.Secure /tmp
http://www.eth0.us/tmp

3.LES Linux Environment Security
Linux Environment Security is intended as a facility to quickly & easily secure RedHat/RPM based environments (i.e: turbo linux, open linux). It does such by enforcing root-only permissions on system binaries (binaries that have no place being
executed by normal users), enforcing root-only path traversal on system paths, enforcing immutable bit on essential rpm package contents (i.e: coreutils), and enforcing immutable bit on shell profile scripts.

4.Removal of Insecure packages

Please check to see the packages that are not needed on a web server. You can use the command rpm -qa to list all the installed rpm packages on the server. From the list remove packages choose the packages that are not required.
Some common examples of unnecessary packages are given below.
mtools
yp-tools
redhat-config-nfs
redhat-config-samba
tftp-server
ypserv
redhat-config-printer-gui
samba
samba-swat
cups
gmp-devel
ElectricFence
doxygen
Xfree86-xfs
redhat-config-printer
cups-libs
samba-common
samba-client

5.Firewall (CSF + LFD)
6.AIDE (Advanced Intrusion Detection Environment)
http://www.cs.tut.fi/~rammer/aide.html

7. Logwatch Installation and configuration
8. ClamAV (virus scanner) Installation with Exim on cPanel servers
9. Installing chkrootkit
10. LibSafe Installation

Sender Policy Framework (SPF)

2010-03-18T00:42:00.002+05:30

Sender Policy Framework (SPF), is an e-mail validation system designed to prevent e-mail spam by addressing a common vulnerability, source address spoofing. SPF allows administrators to specify which hosts are allowed to send e-mail from a given domain by creating a specific DNS SPF record in the public DNS..

example.org. IN SPF "v=spf1 a mx -all"

"v=" defines the version of SPF used. The following words provide mechanisms to use to determine if a domain is eligible to send mail. The "a" and "mx" specify the systems permitted to send messages for the given domain. The "-all" at the end specifies that, if the previous mechanisms did not match, the message should be rejected.
[edit] Mechanisms

Eight mechanisms are defined:
ALL     Matches always; used for a default result like -all for all IPs not matched by prior mechanisms.
A     If the domain name has an address record (A or AAAA) that can be resolved to the sender's address, it will match.
IP4     If the sender is in a given IPv4 address range, match.
IP6     If the sender is in a given IPv6 address range, match.
MX     If the domain name has an MX record resolving to the sender's address, it will match (i.e. the mail comes from one of the domain's mail servers).
PTR     If the domain name (PTR record) for the client's address is in the given domain and that domain name resolves to the client's address (forward-confirmed reverse DNS), match.

EXISTS     If the given domain name resolves to any address, match (no matter the address it resolves to). This is rarely used. Along with the SPF macro language it offers more complex matches like DNSBL-queries.

INCLUDE     If the included (a misnomer) policy passes the test this mechanism matches. This is typically used to include policies of more than one ISP.

Ext2 Vs ext3

2010-03-18T00:30:00.001+05:30

Ext3 filesystem is nothing but next version of ext2 filesystem with journaling support. Ext3 has been structurally implemented same as ext2 so they have same data structures. he most important difference between Ext2 and Ext3 is that Ext3 supports journaling which allows fast recovery from disk problems. You also get reliability and a better performance with ext3. Ext3 is designed to take care of both metadata and data.

Ext3 is a tiny bit slower than ext2 is, but it holds tremendous advantages. There is really only one difference between ext2 and ext3, and that is that ext3 uses a journal to prevent filesystem corruption in the case of an unclean shutdown (ie. before the filesystem is synced to disk). That makes ext3 a bit slower than ext2 since all metadata changes are written to the journal, and then flushed to disk, but on the other hand you don't risk having the entire filesystem destroyed at power failure or if an unwitted person turns the computer off uncleanly.

Inode

2010-03-18T00:22:00.003+05:30

Inode is a unique number given to a file in Unix OS. Every file in Unix has a inode number. Inodes store information of files, such as user and group ownership, access mode (read, write, execute permissions) and type of file. When a file system is created, data structures are created that contain information about files. Each file is associated with an inode that is identified by an inode number

File names and directory implications:

    * Inodes do not contain file names, only file metadata.
    * Unix directories are lists of "link" structures, each of which contains one filename and one inode number.
    * The kernel must search a directory looking for a particular filename and then convert the filename to the correct corresponding inode number if the name is found.

:

Load in the server

2010-03-18T00:05:00.003+05:30

Load : Measure of the amount of work done by a computer systems.
Load average : Average system load over a period of time.

An idle computer has a load number of 0 and each process using or waiting for CPU adds to the load number by 1. Most UNIX systems count only processes in the running (on CPU) or runnable (waiting for CPU) states. However, Linux also includes processes in uninterruptible sleep states (usually waiting for disk activity), which can lead to markedly different results if many processes remain blocked in I/O due to a busy or stalled I/O system. This, for example, includes processes blocking due to an NFS server failure or to slow media (e.g., USB 1.x storage devices). Such circumstances can result in an elevated load average, which does not reflect an actual increase in CPU use (but still gives an idea on how long users have to wait).

Systems calculate the load average as the exponentially damped/weighted moving average of the load number. The three values of load average refer to the past one, five, and fifteen minutes of system operation.

For single-CPU systems that are CPU-bound, one can think of load average as a percentage of system utilization during the respective time period. For systems with multiple CPUs, one must divide the number by the number of processors in order to get a comparable percentage.

For example, one can interpret a load average of "1.73 0.50 7.98" on a single-CPU system as:

    * during the last minute, the CPU was overloaded by 73% (1 CPU with 1.73 runnable processes, so that 0.73 processes had to wait for a turn)
    * during the last 5 minutes, the CPU was underloaded 50% (no processes had to wait for a turn)
    * during the last 15 minutes, the CPU was overloaded 698% (1 CPU with 7.98 runnable processes, so that 6.98 processes had to wait for a turn)

This means that this CPU could have handled all of the work scheduled for the last minute if it were 1.73 times as fast, or if there were two (1.73 rounded up) times as many CPUs, but that over the last five minutes it was twice as fast as necessary to prevent runnable processes from waiting their turn.

In a system with four CPUs, a load average of 3.73 would indicate that there were, on average, 3.73 processes ready to run, and each one could be scheduled into a CPU.

On Linux systems, the load-average is not calculated on each clock tick, but driven by a variable value that is based on the HZ frequency setting and tested on each clock tick. (HZ variable is the pulse rate of particular Linux kernel activity. 1HZ is equal to one clock tick; 10ms by default.) Although the HZ value can be configured in some versions of the kernel, it is normally set to 100. The calculation code uses the HZ value to determine the CPU Load calculation frequency. Specifically, the timer.c:calc_load() function will run the an algorithm every 5 * HZ, or roughly every five seconds. Following is that function in its entirety:

unsigned long avenrun[3];
 
static inline void calc_load(unsigned long ticks)
{
   unsigned long active_tasks; /* fixed-point */
   static int count = LOAD_FREQ;
 
   count -= ticks;
   if (count < 0) {
      count += LOAD_FREQ;
      active_tasks = count_active_tasks();
      CALC_LOAD(avenrun[0], EXP_1, active_tasks);
      CALC_LOAD(avenrun[1], EXP_5, active_tasks);
      CALC_LOAD(avenrun[2], EXP_15, active_tasks);
   }
}

The avenrun array contains 1-minute, 5-minute and 15-minute average. The CALC_LOAD macro and its associated values are defined in sched.h :

define FSHIFT   11  /* nr of bits of precision */
   define FIXED_1  (1<<FSHIFT) /* 1.0 as fixed-point */
   define LOAD_FREQ (5*HZ) /* 5 sec intervals */
   define EXP_1  1884  /* 1/exp(5sec/1min) as fixed-point */
   define EXP_5  2014  /* 1/exp(5sec/5min) */
   define EXP_15 2037  /* 1/exp(5sec/15min) */
 
   define CALC_LOAD(load,exp,n) \
      load *= exp; \
      load += n*(FIXED_1-exp); \
      load >>= FSHIFT;

How to enable tun/tap device with nat

2010-02-26T09:42:00.002+05:30

OpenVZ supports VPN inside a container via kernel TUN/TAP module and device. To allow container #101 to use the TUN/TAP device the following should be done:

Make sure the tun module has been already loaded on the hardware node:

# lsmod | grep tun

If it is not there, use the following command to load tun module: .
# modprobe tun

To make sure that tun module will be automatically loaded on every reboot you can also add it or into /etc/modules.conf (on RHEL see /etc/sysconfig/modules/ directory) or into /etc/sysconfig/vz-scripts/CTID.mount. (echo 'modprobe tun' >> /etc/sysconfig/vz-scripts/CTID.mount)

Granting container an access to TUN/TAP

Allow your container to use the tun/tap device by running the following commands on the host node:

vzctl set 101 --devices c:10:200:rw --save
vzctl set 101 --capability net_admin:on --save

And create the character device file inside the container (execute the following on the host node):

vzctl exec 101 mkdir -p /dev/net
vzctl exec 101 mknod /dev/net/tun c 10 200
vzctl exec 101 chmod 600 /dev/net/tun

Configuring VPN inside container

After the configuration steps above are done it is possible to use VPN software working with TUN/TAP inside container just like on a usual standalone linux box.

The following software can be used for VPN with TUN/TAP:

* Virtual TUNnel (http://vtun.sourceforge.net)
* OpenVPN (http://openvpn.net)

If NAT is needed within the VE, this error will occur on attempts to use NAT:

# iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o venet0 -j MASQUERADE

How to add a new hdd to linux server.

2010-01-26T17:44:00.002+05:30

Issue the command fdisk -l, you can see the new hard disk connected to the server.

For example:
----------------------------------------------------
Disk /dev/sda: 1500.3 GB, 1500301910016 bytes
255 heads, 63 sectors/track, 182401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id System
/dev/sda1   *           1          13      104391   83 Linux
/dev/sda2              14      182401 1465031610   8e Linux LVM

Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes
255 heads, 63 sectors/track, 182401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table
-------------------------------------------------------

Then you need to create a partition in the new server. Using the command 'n', you can create a new partition. Select the partition number and issue the command "w" to write write the partition.

------------------------------------------------------
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.

The number of cylinders for this disk is set to 182401.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
e
Partition number (1-4):
Value out of range.
Partition number (1-4): 1
First cylinder (1-182401, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-182401, default 182401):
Using default value 182401

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

----------------------------------

Then you have to create a file system in the new hard disk.
mkfs -t ext3 /dev/sdb1 or mkfs.ext3 /dev/sdb1

------------------------------------------
[root@localhost ~]# mkfs.ext3 /dev/sdb1
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
183091200 inodes, 366181585 blocks
18309079 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
11175 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
        102400000, 214990848

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information:
done

This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
---------------------------------------------

Then you have to mount the hard disk to the directory /home1

mount /dev/sdb1 /home1

Exim : 451-The server has reached its limit for processing requests from your host.n451 Please try again later.

2010-01-25T04:18:00.000+05:30

451-The server has reached its limit for processing requests from your host.n451 Please try again later.

its probably exim's ratelimiting, add your servers IP's to the whitelist in WHM > Exim Configuration

Also check the value of the 'Maximum Emails a Domain Can Send In 1 Hour' value in WHM > Tweak Settings

retry time not reached for any host after a long failure period

exim_tidydb -t 10m /var/spool/exim retry
exim_tidydb -t 10m /var/spool/exim wait-remote_smtp

How to create a swap file

2010-01-24T09:28:00.000+05:30

To add a swap file:

Determine the size of the new swap file in megabytes and multiply by 1024 to determine the number of blocks. For example, the block size of a 64 MB swap file is 65536.
At a shell prompt as root, type the following command with count being equal to the desired block size:
```
dd if=/dev/zero of=/swapfile bs=1024 count=65536
```
Setup the swap file with the command:
```
mkswap /swapfile
```
To enable the swap file immediately but not automatically at boot time:
```
swapon /swapfile
```
To enable it at boot time, edit /etc/fstab to include the following entry:
```
/swapfile swap swap defaults 0 0
```
The next time the system boots, it enables the new swap file.
After adding the new swap file and enabling it, verify it is enabled by viewing the output of the command cat /proc/swaps or free.

TCP vs UDP

2010-01-24T08:55:00.000+05:30

TCP:

Reliability: TCP is connection-oriented protocol. When a file or message send it will get delivered unless connections fails. If connection lost, the server will request the lost part. There is no corruption while transferring a message.

Ordered: If you send two messages along a connection, one after the other, you know the first message will get there first. You don't have to worry about data arriving in the wrong order.

Heavyweight: - when the low level parts of the TCP "stream" arrive in the wrong order, resend requests have to be sent, and all the out of sequence parts have to be put back together, so requires a bit of work to piece together.

Streaming: Data is read as a "stream," with nothing distinguishing where one packet ends and another begins. There may be multiple packets per read call.

Examples: World Wide Web (Apache TCP port 80), e-mail (SMTP TCP port 25 Postfix MTA), File Transfer Protocol (FTP port 21) and Secure Shell (OpenSSH port 22) etc.

UDP:

Reliability: UDP is connectionless protocol. When you a send a data or message, you don't know if it'll get there, it could get lost on the way. There may be corruption while transferring a message.

Ordered: If you send two messages out, you don't know what order they'll arrive in i.e. no ordered

Lightweight: No ordering of messages, no tracking connections, etc. It's just fire and forget! This means it's a lot quicker, and the network card / OS have to do very little work to translate the data back from the packets.

Datagrams: Packets are sent individually and are guaranteed to be whole if they arrive. One packet per one read call.

Examples: Domain Name System (DNS UDP port 53), streaming media applications such as IPTV or movies, Voice over IP (VoIP), Trivial File Transfer Protocol (TFTP) and online multiplayer games etc

Simple steps for SSH Server Hardening.

2010-01-24T08:39:00.000+05:30

SSH Server Hardening in one of the security part to secure your server.Refer following steps to secure SSH.

root@serevr[~]#pico /etc/ssh/sshd_config
Uncomment #Protocol 2, 1
Change to Protocol 2
Append these lines to the bottom:
LoginGraceTime 120
IgnoreRhosts yes
X11Forwarding no

Save file and restart the SSH service.
root@serevr[~]#/etc/rc.d/init.d/sshd restart

Note : SSH Protocol one based servers are facing many automated root kits attacks.As a result to step up the security Protcol 2 should be enabled on server.The reason to use SSH Protocol 2 on any webserver is that it is more secure as compare to protocol 1.

Basic sed tricks

2010-01-22T19:00:00.002+05:30

What is sed? - sed is stream editor, a Unix tool for working with streams of text data. See the awful truth about sed.
How do you substitute strings with sed? - Use ’s/old/new’ command, so sed ’s/hello/goodbye/’ would substitute the occurrence of the word hello to goodbye.
How do you inject text with sed? - & in the substitution string defines the pattern found in the search string. As an example, here’s us trying to find a word ‘hello’ and replacing it with ‘hello and how are you’:
echo ‘hello there’ | sed ’s/^hello/& and how are you/’
Can I find several patterns and refer to them in the replacement string? - Yes, use (pattern) and then refer to your patterns as \1, \2, \3 and so on.
If the string is ‘old old old’ and I run ’s/old/new’, I get ‘new old old’ as the result. I need ‘new new new‘. - You forgot the global modifier, which would replace every occurrence of the pattern with the substitution. ’s/old/new/g‘ will work.
But I want ‘old old new’ from the previous example. - Just use the numeric modifier saying you want the third occurrence to be replaced. ’s/old/new/3‘ will work.
I wrote a rather complex sed script. How do I save and run it? - Assuming that your file is named myscript1.sed, you can invoke sed -f myscript1.sed.
How do I delete trailing whitespaces from each line? - sed ’s/[ \t]*$//’ Here we’re replacing any occurrence of a space or a tab with nothing. Check sed one-liners for more examples.
How do you print just a few first lines of the file? - sed 1q will give you just the first line, sed 10q the first 10 lines.
How do you replace a pattern only if it’s found, so that it’s executed faster? - Nest the replacement statement: sed ‘/old/ s/old/new/g’ file.txt

How to assign a range of IP's to server

2010-01-22T06:26:00.000+05:30

Create a file /etc/sysconfig/network-scripts/ifcfg-eth0-range0 add the following entries

IPADDR_START=192.168.0.0
IPADDR_END=192.168.0.100
CLONENUM_START=1

Save it and restart network
/etc/init.d/network restart

Mbox vs Maildir: Mail Storage Formats

2010-01-20T18:51:00.000+05:30

The Unix world has two ways of storing mail messages, the traditional mbox format and the newer maildir format. Postfix and Dovecot supports the two mail storage format so you can use any format, but I highly recommend you use the maildir format.

Mbox Format:

This is the traditional way of storing mail messages in the Unix world. In this format, a regular text file which serves as the mail user’s mailbox file is created.

How Mbox works
Receiving and storing a mail

   1. Lock the mailbox.
   2. Append the header (usually “From [sender's email address] [date and time received]“) and the mail into the mailbox file.
   3. Unlock the mailbox.

Retrieving a mail

   1. Lock the mailbox.
   2. Locate and read the mail.
   3. Update the mail status flag.
   4. Unlock the mailbox.

Deleting a mail

   1. Lock the mailbox.
   2. Move the contents of the mailbox, beginning from the position right after the mail to be deleted until the end of the mailbox, into the position of the mail to be deleted.
   3. Reduce the size of the mailbox file by the size of the deleted mail.
   4. Unlock the mailbox.

Searching a mail

   1. Lock the mailbox.
   2. Search the mailbox.
   3. Unlock the mailbox.

Advantages

    * Format is universally supported.
    * Appending a new mail into the mailbox file is fast.
    * Searching text inside a single mailbox file is fast.

Disadvantages

    * Has file locking problems.
    * Has problems when used with network file systems.
    * Format is prone to corruption.

The Maildir Format

This is a new way of storing mail messages. In this format, a directory usually named Maildir is created for each mail user.
Under this directory are three more directories named new, cur and tmp.

How Maildir works
Receiving and storing a mail

   1. Create a unique file in the tmp directory.
   2. Write the mail into the newly created file.
   3. Move the completely written mail into the new directory.

Retrieving a mail

   1. Locate and read the mail.
   2. Move the mail from new into the cur directory and append the mail status flag into the filename.

Deleting a mail

   1. Delete the file containing the mail.

Searching a mail

   1. Search each and every mail file.

Advantages

    * Locating, retrieving and deleting a specific mail is fast.
    * Minimal to no file locking needed.
    * Can be used on network file system.
    * Immune to mailbox corruption (assuming the hardware will not fail).

Disadvantages

    * Some filesystems may not efficiently handle a large number of small files.
    * Searching text, which requires all mail files to be opened is slow.

Unable to start apache " pid file /usr/local/apache/logs/httpd.pid overwritten — Unclean shutdown of previous Apache run? semget: No space left on device"

2010-01-20T18:27:00.000+05:30

If you are unable to start apache and you are getting the error log as

[Sat Oct 10 00:11:01 2008] [warn] pid file /usr/local/apache/logs/httpd.pid overwritten — Unclean shutdown of previous Apache run?
semget: No space left on device

It means There is no more space left in Semaphore Arrays for Apache.
semaphore is a location in memory whose value can be tested and set by more than one process.
you can check the semaphore arrays on your server using the following command

ipcs -s

It results

------ Semaphore Arrays --------
key semid owner perms nsems
0x00000000 360448 nobody 600 1
0x00000000 393217 nobody 600 1
0x00000000 425986 nobody 600 1
0x00000000 458755 nobody 600 1
0x00000000 524292 nobody 600 1
0x00000000 1114117 nobody 600 1
0x00000000 1441798 nobody 600 1
0x00000000 3604487 nobody 600 1
0x00000000 3702792 nobody 600 1
0x00000000 3768329 nobody 600 1
0x00000000 6422538 nobody 600 1
0x00000000 7077899 nobody 600 1

If here you get big list of semaphores it means some semaphores are stuck. You can clear them out with this command:

for i in `ipcs -s | awk '/nobody/ {print $2}'`; do (ipcrm -s $i); done

Restart apache
#/etc/init.d/httpd restart

VPS : tty device is not owned by group `tty’

2010-01-05T20:20:00.000+05:30

If you’re unable to SSH into a VPS server, try accessing the VPS from the OpenVZ hardware node.

[root@VS ~]# vzctl enter VID
entered into VE 1022
mesg: error: tty device is not owned by group `tty’

Here you can see that there is an error related to tty. This error can be resolved by changing the group of the tty files.

vzctl exec VIS'chgrp tty /dev/ttyp* /dev/ptyp*'

There can be many other reasons related to SSH failures.

You might like check on udev package also (You will normally find this issue on CentOS5)

Find the udev rpm on the VPS server,

root@vps1 [/]# rpm -qa | grep udev
udev-095-14.16.el5

Remove it from the server
root@vps1 [/]# rpm -e –nodeps udev

Once this is done, your SSH should start working fine.

Installing fantastico on a cPanel Server

2009-12-23T21:31:00.000+05:30

Here are the steps:-
============

Login to server WHM >> Plugins >> Fantastico De Luxe WHM Admin >> Click here >> Select a version from the drop down menu >> Follow the remaining installation steps, using the default information.

If the Fantastico install option is not available,then we have to download Fantastico manually onto our server.

=========================================
1) Login to the server via ssh

2) Change the folder using the command:

[root@localhost ~]#cd /usr/local/cpanel/whostmgr/docroot/cgi

3) Download the Fantastico install file using the command

[root@localhost ~]#wget http://www.netenberg.com/files/free/fantastico_whm_admin.tgz

4) Extract the install file using the command:

[root@localhost ~]#tar -xzpf fantastico_whm_admin.tgz

5) Remove the install file using the command:

[root@localhost ~]#rm -rf fantastico_whm_admin.tgz

6) Log out of the SSH connection.

7) log back into cPanel.

8)Go through Plugins >> Fantastico De Luxe WHM Admin

9) Continue the install using the above mentioned steps.
========================================

Fantastico Showing Blank Page

2009-12-23T21:28:00.002+05:30

Fantastico is showing blank page after installation.New installation was also giving the blank page.

FIX:-
====
Change the following on config.php file.

#define(”PLUGIN_ROOTDIR”,”/tmp”);
define(”PLUGIN_ROOTDIR”,”plugins”);

Cause:-
The server is PHP-SUEXEC enabled so the plugin_rootdir should be given
as “plugins” in config.php file.

Fix for memory limit error in joomla site

2009-12-23T20:21:00.000+05:30

You could see memory limit error on joomla sites. Even though you increase memory limit on php.ini file, it will not solve.

In Apache error logs you can find the following:-

===================================================
[Wed Feb 6 05:56:26 2008] [error] (22)Invalid argument: setrlimit: failed to set memory limit
[Wed Feb 7 09:48:26 2008] [error] (22)Invalid argument: setrlimit: failed to set memory limit
===================================================
Fix:-
Remove the following entries from apache configuration file.

1. RLimitMEM 519640064
2. RLimitCPU 240

Restart apache after this. This will fix the issue

Error "This application is currently not available” in fantastico

2009-12-23T20:16:00.002+05:30

The user is getting the following error while accessing fantastico :
This application is currently not available

Fix:-
====
You have to make register_global = On in /usr/local/cpanel/3rdparty/etc/php.ini

“cannot connect to mysql ” in fantastico

2009-12-23T20:14:00.000+05:30

If you are getting an error like “cannot connect to mysql ” in fantastico
then check if the soft link is there in /tmp. If there is no softlink.Issue the following command:-

[root@bigboy ~]#ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock

Configuration files in cpanel server

2009-12-23T19:56:00.000+05:30

Apache:-

/usr/local/apache/ bin->Apache binaries are stored here
/usr/local/apache/conf–>configuration files – httpd.conf
/usr/local/apache/cgi-bin->Cgi bin directory
/usr/local/apache/domlogs–>domain log files are stored here
/usr/local/apache/htdocs->default doucument root of the server
/usr/local/apache/include–>contains header files
/usr/local/apache/modules–>Contains shared object (.so) files
/usr/local/apache/logs–>apache logs contains access_log, errorlog and suexec_log

Exim:-

->/etc/exim.conf – exim configuration file
->/etc/localdomains – list of the domains which are allowed to relay mail
->/var/log/exim_mainlog – exim main log file
-> /var/log/exim_rejectlog – Contains the logs for the rejected mails.
->/var/log/exim_paniclog – Contains exim errors
->/var/spool/exim/input-Mail queue for exim
->/etc/valiases/domainname.com- Email forwarders and catchall.
->/etc/vfilters/domainname.com-Email filter
->/home/username/etc/domainname/passwd-POP authentication file

ProFTPD:-

-> /etc/proftpd-configuration file
->/var/log/messages-ftp logs
->/etc/proftpd/username- All the ftp accounts and password will be listed here.

Pure-FTPD:-

->/etc/pure-ftpd.conf-Pureftpd configuration file.
->/etc/pure-ftpd/ip-address-document root for the anonymous ftp

Mysql:-

/etc/my.cnf->configuration file
/root/.my.cnf->Contains the root password
/var/lib/mysql –Data directory which contains all the MySql databases.

SSHD:-

/etc/ssh/sshd_config->configuarton file
/var/log/messages-> Log file
/etc/banner->Contains the banner to be displayed

Named:-

/etc/named.conf->Main configuration file
/var/named->Directory which contains the db records
/var/log/messages-> Log file

Cpanel Configuration files:-

/usr/local/cpanel-/bin –> cpanel binaries
/usr/local/cpanel/cgi-sys –> Contains cgi files like formmail.cgi etc
/usr/local/cpanel-/base –> phpmyadmin, squirrelmail, skins, webmail etc
/usr/local/cpanel-/logs -> cpanel access log, error log etc
/usr/local/cpanel/ 3rdparty/ –Fantastico,mailman files are located here
/usr/local/cpanel-/addons –> AdvancedGuestBook, phpBB etc
/var/cpanel/users/username – >cpanel user file
/var/cpanel/cpanel.config –> cpanel configuration file.
/var/cpanel/resellers –> Reseller configuration files.
/var/log/dcpumon –> Top log process
/etc/wwwacct.conf –> account creation default file
/etc/cpupdate.conf – >cPanel Updation Config file
/etc/cpbackup.conf –> Backup configuration file
/var/cpanel/bandwidth –> Contains bandwidth usage details of the domains.

Name server and IP configuration files:-

/etc/sysconfig/network –Network configuration files
/etc/hosts->Contains hostname of the server
/etc/resolv.conf –> Resolver Configuration
/etc/nameserverips –>Contains the name server IP details
/etc/ips –>List of all the ip addresses except the shared ip on the server.
/etc/ipaddrpool – >ip addresses which are free
/etc/ips.dnsmaster –> name server ips

How to setup Wild Card Entry For a Domain

2009-12-23T18:56:00.003+05:30

Edit the DNS zone file:-

Open the zone db file corresponding to the domain (For eg, domain.com)
[root@localhost ~]#vi /var/named/domain.com.db
Add the following line:-
================
* IN A IPaddress
=================
save and exit
restart named

[root@localhost ~]# /etc/init.d/named restart

Edit httpd conf file:-

[root@localhost ~]#vi /usr/local/apache/conf/httpd.conf

Add the following entry:-

===================
server alias *.domain.com
===================

save and exit

restart httpd

How to check DNS zone file configuration for errors

2009-12-23T18:51:00.001+05:30

You can use the named-checkzone command to check the zone db for errors:-

[root@server]# named-checkzone abhionlinux.com /var/named/abhionlinux.com.db
Output:-
zone abhionlinux.com/IN: loaded serial 12
OK

or

[root@server]# named-checkconf /etc/named.conf

Install YUM in the server

2009-12-23T18:33:00.002+05:30

for file in \
gmp-4.1.4-10.el5.x86_64.rpm \
readline-5.1-1.1.x86_64.rpm \
python-2.4.3-21.el5.x86_64.rpm \
libxml2-2.6.26-2.1.2.1.x86_64.rpm \
libxml2-python-2.6.26-2.1.2.1.x86_64.rpm \
expat-1.95.8-8.2.1.x86_64.rpm \
python-elementtree-1.2.6-5.x86_64.rpm \
sqlite-3.3.6-2.x86_64.rpm \
python-sqlite-1.1.7-1.2.1.x86_64.rpm \
elfutils-0.125-3.el5.x86_64.rpm \
rpm-python-4.4.2-48.el5.x86_64.rpm \
m2crypto-0.16-6.el5.2.x86_64.rpm \
python-urlgrabber-3.1.0-2.noarch.rpm \
yum-3.2.8-9.el5.centos.1.noarch.rpm
do rpm -Uvh http://mirror.centos.org/centos-5/5.2/os/x86_64/CentOS/$file;
done

DB_RUNRECOVERY: Fatal error, run database recovery

2009-12-23T13:40:00.001+05:30

If you are getting error message like this when you are trying to do an yum update.

Error message like ->
============================================
ror: error(-3097 getting "system-config-display.mo" records from Basenames index
rpmdb: PANIC: fatal region error detected; run recovery
error: db4 error(-3097 from dbcursor->c_get: DB_RUNRECOVERY: Fatal error, run database recovery
error: error(-3097 getting "system-config-display.mo" records from Basenames index
rpmdb: PANIC: fatal region error detected; run recovery
error: db4 error(-3097 from dbcursor->c_get: DB_RUNRECOVERY: Fatal error, run database recovery
error: error(-3097 getting "system-config-display.mo" records from Basenames index
rpmdb: PANIC: fatal region error detected; run recovery
error: db4 error(-3097 from dbcursor->c_get: DB_RUNRECOVERY: Fatal error, run database recovery
error: error(-3097 getting "system-config-display.mo" records from Basenames index
************************************************** *****

try the following steps.

rm -f /var/lib/rpm/__db*
rpm -vv --rebuilddb
rpm -Va
yum update

How to increase the size of /tmp partition in Linux?

2009-12-22T19:57:00.000+05:30

Proceed with the given steps:-
========================
1)Stop MySql service and process kill the tailwatchd process.

[root@localhost ~]# /etc/init.d/mysqld stop
Stopping MySQL: [ OK ]
[root@localhost ~]#pstree -p | grep tailwatchd
Find the tailwatchd process id and kill it
[root@localhost ~]# kill -9 2522

2)Take a backup of /tmp as /tmp.bak
[root@localhost ~]#cp -prf /tmp /tmp.bak

3)Create a 2GB file in the avaliable freespace

==============================
[root@localhost dev]# dd if=/dev/zero of=/usr/tmpDSK bs=1024k count=2048
2048+0 records in
2048+0 records out
2147483648 bytes (2.1 GB) copied, 73.6908 seconds, 29.1 MB/s
==============================

[root@localhost dev]# du -sch /usr/tmpDSK
2.1G /usr/tmpDSK
2.1G total

4)Assign ext3 filesystem to the file
====================================
[root@localhost dev]# mkfs -t ext3 /usr/tmpDSK
mke2fs 1.39 (29-May-2006)
/usr/tmpDSK is not a block special device.
Proceed anyway? (y,n) y
Filesystem label=
OS type: Linux
262144 inodes, 524288 blocks
26214 blocks (5.00%) reserved for the super user
First data block=0
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 25 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
====================================
5) Check the file system type:-

[root@localhost dev]# file /usr/tmpDSK

/usr/tmpDSK: Linux rev 1.0 ext3 filesystem data (large files)
Note:-
=====
You may also use the following comands for making ext3 file system on a file:
[root@localhost dev]#mkfs.ext3 /usr/tmpDSK
[root@localhost dev]#mke2fs /usr/tmpDSK

6)Unmount /tmp partition

[root@localhost dev]#umount /tmp

7))Mount the new /tmp filesystem with noexec

[root@localhost dev]#mount -o loop,noexec,nosuid,rw /usr/tmpDSK /tmp

8) Set the correct permission for /tmp

[root@localhost dev]# install -d –mode=1777 /tmp
[root@localhost dev]# ls -ld /tmp
drwxrwxrwt 3 root root 4096 Feb 6 08:42 /tmp
( you may use the command chmod 1777 /tmp for doing the same )
==========================

[root@localhost dev]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda9 28G 6.4G 20G 25% /
/dev/sda8 99M 10M 84M 11% /boot
tmpfs 500M 0 500M 0% /dev/shm
/usr/tmpDSK 2.0G 68M 1.9G 4% /tmp
==========================
7)Restore the content of old /tmp.bkp directory

[root@localhost dev]# cp -rpf /tmp.bak/* /tmp

8) Restart the mysql and tailwathchd services.

[root@localhost dev]# /etc/init.d/mysql start
[root@localhost dev]# /scripts/restartsrv_tailwatchd

9)Edit the fstab and replace /tmp entry line with :-
=========================================
/usr/tmpDSK /tmp ext3 loop,noexec,nosuid,rw 0 0=========================================
10) Mount all filesystems

[root@localhost dev]#mount -a

Check it now:-
============================
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda9 28G 6.4G 20G 25% /
/dev/sda8 99M 10M 84M 11% /boot
tmpfs 500M 0 500M 0% /dev/shm
/usr/tmpDSK 2.0G 68M 1.9G 4% /tmp
============================
Done.

How to prevent the Syn flood attack?

2009-12-22T19:32:00.002+05:30

1)Enable SYN cookies mechanism in the server.

SYN cookies mechanism can be enabled in the following way:

[root@server src]## echo 1 > /proc/sys/net/ipv4/tcp_syncookies

2)Increase the backlog queue:-

A tcp_max_backlog variable_defines how many half-open connections can be kept by the backlog queue.

change the default size of the backlog queue to 2048 by executing the the sysctl command:

[root@server src]# sysctl -w net.ipv4.tcp_max_syn_backlog="2048"

Getting custom php.ini working on php-cgi

2009-12-22T16:40:00.001+05:30

1, Copy the servers default php.ini to your home directory

2, Make the following directory in user home directoy and chown to user:user
cgi-bin

3, Create a file php.cgi in cgi-bin with the following content
#!/bin/sh
exec /usr/local/cpanel/cgi-sys/php5 -c /home/user/public_html/

4, Chmod +x php.cgi and chown the file to user:user.

5, Add the following in the .htaccess.

Action application/x-httpd-php5 /cgi-bin/php.cgi

Installing a custom module in cpanel server

2009-12-22T11:39:00.000+05:30

To install a custom module:

1. Download and unzip it into /var/cpanel/easy/apache/custom_opt_mods/.
2. When logged into your server as root, you can install any module listed below by running the following commands. Be sure to replace $NAME.tar.gz with the filename of the module you wish to download:

wget http://easyapache.cpanel.net/optmods/$NAME.tar.gz
tar -C /var/cpanel/easy/apache/custom_opt_mods -xzf $NAME.tar.gz

For example:
If you want to install mod_python

cd /var/cpanel/easy/apache/custom_opt_mods

wget http://twiki.cpanel.net/twiki/pub/EasyApache3/CustomMods/custom_opt_mod-mod_python.tar.gz
tar -C /var/cpanel/easy/apache/custom_opt_mods -xzf custom_opt_mod-mod_python.tar.gz

Reference : http://docs.cpanel.net/twiki/bin/view/EasyApache3/CustomMods

Install Wine on CentOS 5

2009-12-17T19:21:00.002+05:30

Trying to install wine using the usual yum command but here is what it says when giving the following command.

shell>> yum install wine
Loading “fastestmirror” plugin
Loading mirror speeds from cached hostfile
* base: centose.centos.org
* updates: centosj.centos.org
* addons: centosh3.centos.org
* extras: centose-msync-dvd.centos.org
Excluding Packages in global exclude list
Finished
Setting up Install Process
Parsing package install arguments
No package wine available.
Nothing to do

Well the reason is Wine software is not a part of standard CentOS. There is a section on 3rd party repositories called RPMForge. So we will proceed installing the Repositories.

1.) You should make sure that you have Priorities installed

yum-priorities is available in the CentOS 5 repositories:

yum install yum-priorities

Plugins are enabled in CentOS 5 by default

Make sure that yum-priorities is enabled by editing the /etc/yum/pluginconf.d/priorities.conf file, and ensuring that it contains the following lines:

[main]
enabled=1

Download the rpmforge-release package. Choose one of the two links below, depending on your architecture. If you are unsure of which one to use you can check your architecture with the command uname -i

for i386 http://apt.sw.be/redhat/el5/en/i386/RPMS.dag/rpmforge-release-0.3.6-1.el5.rf.i386.rpm

Install DAG’s GPG key

rpm –import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
Verify the package you have downloaded

rpm -K rpmforge-release-0.3.6-1.el5.rf.*.rpm

Security warning: The rpmforge-release package imports GPG keys into your RPM database. As long as you have verified the package and trust Dag then it should be safe.

Install the package

rpm -i rpmforge-release-0.3.6-1.el5.rf.*.rpm

This will add a yum repository config file and import the appropriate GPG keys. At this point, you can set the priority of the RPMForge repository, and also of the CentOS repositories if you have not done so yet.

Test with this command:

yum check-updateIt should output these two lines:

Loading “priorities” plugin
…
76 packages excluded due to repository priority protectionsThe number above may differ, but there should be several packages shown as being excluded.

If so then it looks like things are working so try installing something like this

yum -–enablerepo=rpmforge install wine

Thats all Wine is installed.
shell>> which wine
/usr/bin/wine

Exim Commands

2009-12-16T16:35:00.000+05:30

Check emails in mail queue

root@server [~]# exim -bp

Count number of emails in mail queue

root@server [~]# exim -bpc

Count number of frozen emails in mail queue

root@server [~]# exim -bp | grep frozen | wc -l

Delete forzen emails from the mail queue

exim -bp | awk ‘$6~”frozen” { print $3 }’ | xargs exim -Mrm

Count emails for an email account/domain

exim -bp | grep username@domain.com | wc -l

Delete emails for an email account

exim -bp | grep username@domain.com | awk ‘{print $3}’ | xargs exim -Mrm ;

Delete emails sent through scripts

exim -bp | grep “<>” | awk {’print $3}’ | xargs exim -Mrm

Count number of emails in queue for a domain/email account

exim -bp | tr ‘\n’ + | sed -e “s/++/=/g” | tr -d + | tr = ‘\n’ | awk ‘{print $5}’ | sort -n | uniq -c | sort -n

Delete emails for root

exim -bp | grep root@server.hostname.com | awk ‘{print $3}’ | xargs exim -Mrm ;

abhionlinux

Softaculous : Your license is not active or it has expired. If your license has expired, please renew it to continue using this Software.

How to change the time zone for a domain

special device *device-name* does not exist : LVM

Site error: the file /usr/local/cpanel/whostmgr/docroot/cgi/softaculous/enduser/main/functions.php requires the ionCube PHP Loader ioncube_loader_lin_5.2.so to be installed by the site administrator. - Softaculous

RKhunter installation

Kaltura Installation

ffmpeg-php installation

flvtool2

create db and user in mysql

FFmpeg installation

MP4Box installation

Missing pentaho while installing Kaltura

how to install memcached on centos

How to reset a kloxo admin password

Clipbucket admin area showing blank page

Connection to the server was reset - PHPmotion

SERVICE CURRENTLY NOT AVAILABLE! - Roundcube

How to install memcache in the server

How to clear cache memory(RAM) in linux

.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable

FFmpeg :: make: *** [ffmpeg_frame.lo] Error 1

How to restore mysql database in linux plesk

How to install commands host, dig and nslookup in linux.

How to check open ports in linux

How to reset sshd config using WHM

Wrong mysql disk usage in cpanel.

/bin/mv: Argument list too long

FFmpeg :: make: *** [ffmpeg_frame.lo] Error 1/

How to install yasm

How to install Yamdi

How to install qt-faststart with ffmpeg

Spool file is locked (another process is handling this message) : Unable to send emails ,exim

How to enable IP rotation in exim.

Unable to load dynamic library ‘/usr/lib64/php/modules/ffmpeg.so

phpize : command not found

How to install GIT

Yum update failed.

Command to check the performance of the hard disk.

Request exceeded the limit of 10 internal redirects due to probable configuration error. Use ‘LimitInternalRecursion’ to increase the limit ifnecessary. Use ‘LogLevel debug’ to get a backtrace

Linux Plesk Back end files.

Move worpress site from subfolder to root

Moodle : ERROR: Could not find or create a directory (/home/username/public_html/uploaddata/16)

Unable to login to Moodle site "Your session has timed out. Please login again"

PGsql database not showing in cpanel

Error while installin Xdebug pecl module

Change exim interface IP address

How to upload multiple files using ftp in command line mode.

Uploading Error in WordPress. “Unable to create directory-Is its parent directory writable by the server?"

how to set time zone in VPS node (OpenVZ)

Phpmotion : Uploading video asks .pl-File to download

Phpmotion : Uploading video asks .pl-File to download

word-press url change, site not loading correctly

Queueprocd Failed.

How to check the server is Suexec

limit number of connection to a server using IPTABLES

How to increase maximum execution time using htaccess

OpenSSH Public Key Authentication

Video uploading throws error -- Failed to find flength file.

PhpMotion Installation

Servers - Linux/Unix server

PHP Settings

Apache Web Server

Downloading PHPmotion

General Instructions

Additional Instructions

Installing to a Sub-Directory

Clipbucket Video error : "This video might not work properly "

RVSkin installation in cpanel server

Send/Recieve email using Telnet

How to set multiple IP addresses using Linux command line

Install and Configure Cacti Network Graphing Tool

Required software(s)

Configure MySQL server

Install snmpd

Install cacti

Install cacti tables

Configure cacti

Configure httpd

Setup cacti cronjob

special device device-name does not exist : LVM