Diffrence between nginx & apache :-

Apache is a process-based server, while nginx is an event-based web server.Nginx known as “engineX” probably the best-known asynchronous server and Apache is undoubtedly the best known process-based server.

The main advantage of the asynchronous approach is scalability. In a process-based server, each simultaneous connection requires a thread which incurs significant overhead. An asynchronous server, on the other hand, is event-driven and handles requests in a single (or at least, very few) threads.

While a process-based server can often perform on par with an asynchronous server under light loads, under heavier loads they usually consume far too much RAM which significantly degrades performance. Also, they degrade much faster on less powerful hardware or in a resource-restricted environment such as a VPS.

Pulling numbers from thin air for illustrative purposes, serving 10,000 simultaneous connections would probably only cause Nginx to use a few megabytes of RAM whereas Apache would probably consume hundreds of megabytes (if it could do it at all).

Nginx+cPanel+Apache= Performance boosted secured hosting server

How NginxAdmin will help your cPanel server to increase the performance ?

NginxAdmin is WHM interface of Nginx installer for cPanel server. This plugin will increase your server performance and decrease the server Apache Load. So you can host more websites in a cPanel server than usual.Nginx is known for its high performance, stability, rich feature set, simple configuration, and low resource consumption.Unlike traditional servers, Nginx doesn’t rely on threads to handle requests. Instead it uses a much more scalable event-driven architecture. This architecture uses small, but more importantly, predictable amounts of memory under load.

Even if you don’t expect to handle thousands of simultaneous requests, you can still benefit from Nginx’s high-performance and small memory footprint. Nginx scales in all directions: from the smallest VPS all the way up to clusters of servers.

To install copy and execute following lines :-

# cd /usr/local/src
# wget http://nginxcp.com/nginxadmin2.8-stable.tar
# tar -xvf nginxadmin2.8-stable.tar
# cd publicnginx
# ./nginxinstaller install
# /etc/init.d/httpd restart

Troubleshooting Installation:-

If you receive any pyaml related error or the following error

—————————–
Welcome to the Nginx Admin installer……Starting Install
Generating vhosts…
Traceback (most recent call last):
File “/scripts/createvhosts.py”, line 2, in ?
import yaml
File “/usr/lib/python2.4/site-packages/PyYAML-3.10-py2.4-linux-i686.egg/yaml/__init__.py”, line 26
SyntaxError: ‘yield’ not allowed in a ‘try’ block with a ‘finally’ clause
Installing WHM interface…
deploying booster rockets
Traceback (most recent call last):
File “/usr/local/src/publicnginx/nginxinstaller2″, line 9, in ?
import createvhosts
File “/usr/local/src/publicnginx/createvhosts.py”, line 2, in ?
import yaml
File “/usr/lib/python2.4/site-packages/PyYAML-3.10-py2.4-linux-i686.egg/yaml/__init__.py”, line 26
SyntaxError: ‘yield’ not allowed in a ‘try’ block with a ‘finally’ clause
——————————

Then run execute following commands ….
For i686 architecture :-

# easy_install Pyyaml==3.09
# rm -f /usr/lib/python2.4/site-packages/PyYAML-3.10-py2.4-linux-i686.egg

For x86_64 architecture :-

# easy_install Pyyaml==3.09
# rm -f /usr/lib/python2.4/site-packages/PyYAML-3.10-py2.4-linux-x86_64.egg

Then Again run the following commands :-

# ./nginxinstaller install
# /etc/init.d/httpd restart

Now Nginx run on the port no:80 and apache run on the port no.8081.You can manage the nginx through WHM >> Main >> Nginx Admin

To uninstall nginx use following :-

#  cd /usr/local/src
#  wget http://nginxcp.com/nginxadmin2.8-stable.tar
#  tar xf nginxadmin2.8-stable.tar
#  cd publicnginx
#  ./nginxinstaller uninstall

Enjoy Linux…!!!!

First of all installing the EPEL repository:-

[p-root@unixsurgeon ~]# rpm -Uvh http://download.fedora.redhat.com/pub/epel/5Server/i386/epel-release-5-4.noarch.rpm

Retrieving http://download.fedora.redhat.com/pub/epel/5Server/i386/epel-release-5-4.noarch.rpm
warning: /var/tmp/rpm-xfer.toDVXj: Header V3 DSA signature: NOKEY, key ID 217521f6
Preparing…                ########################################### [100%]
1:epel-release              ########################################### [100%]

Install nginx:-

[p-root@unixsurgeon ~]# yum install nginx

It will install nginx and ask gpg-key for EPEL, accept with yes option.

Now start your nginx web server.

[p-root@unixsurgeon ~]# service nginx start

Starting nginx:                                            [  OK  ]

The default document root of nginx server :- /usr/share/nginx/html
And the config file path is :-  /etc/nginx/nginx.conf
Now open your browser and type 127.0.0.1 , it will open your default nginx page like below:-

http://127.0.0.1

The Default Document root is /usr/share/nginx/html….you should now put your content in a location of your choice and edit the root configuration directive in the nginx configuration file /et/nginx/nginx.conf.

Solution :-

The issue with directory permissions or directory ownership of the directory where PHP keeps its session files.

Locate the directory where sessions are stored in the php.ini file. It will look something like this, although the exact path will vary depending on the distro and any customizations you may have made yourself:

session.save_path = “/var/lib/php/session”

Now check the permissions of that directory and make sure that the web server has permissions to access it.

You may need to either change ownership of the directory, e.g.:

# chown user:group /var/lib/php/session

and substitute “user” for the actual username and “group” for the actual group, and /var/lib/php/session for the actual session save path.

Alternatively, just change the permissions of the directory so it’s world readable and writable:

# chmod 0777 /var/lib/php/session
Enjoy Linux…!!!!

In Linux….we use a whole partition of a physical hard disk for swapping. However, with the 2.6 Linux kernel, swap files are just as fast as swap partitions, although Red Hat recommends using a swap partition. Just Assume that you may upgrade the amount of RAM in your system from 1024 MB to 2048 MB, but there is only 2048 MB of swap space. It might be advantageous to increase the amount of swap space to approx 2 times of your physical RAM it means 4096 MB if you perform memory-intense operations or run applications that require a large amount of memory. The administrative flexibility of swap files outweighs that of partitions; since modern high capacity hard drives can remap physical sectors, no partition is guaranteed to be contiguous. You can add swap file as a dedicated partition or use following instructions to create a swap file.

You have three options: create a new swap partition, create a new swap file, or extend swap on an existing LVM2 logical volume. It is recommended that you extend an existing logical volume.

1. Extending Swap on an LVM2 Logical Volume :-

To extend an LVM2 swap logical volume login through root user (assuming /dev/VolGroup00/LogVol01 is the volume you want to extend):

1. Disable swapping for the associated logical volume:

# swapoff -v /dev/VolGroup00/LogVol01

2.  Resize the LVM2 logical volume by 2o48 MB:

# lvm lvresize /dev/VolGroup00/LogVol01 -L +2048M

3.  Format the new swap space:

# mkswap /dev/VolGroup00/LogVol01

4. Enable the extended logical volume:

# swapon -va

5. Test that the logical volume has been extended properly:

# cat /proc/swaps # free

2. Creating an LVM2 Logical Volume for Swap :-

To add a swap volume group login through root user (assuming /dev/VolGroup00/LogVol02 is the swap volume you want to add):

1. Create the LVM2 logical volume of size 2048 MB:

# lvm lvcreate VolGroup00 -n LogVol02 -L 2048M

2. Format the new swap space:

# mkswap /dev/VolGroup00/LogVol02

3. Add the following entry to the /etc/fstab file:

/dev/VolGroup00/LogVol02   swap     swap    defaults     0 0

4. Enable the extended logical volume:

# swapon -va

5. Test that the logical volume has been extended properly:

# cat /proc/swaps # free

3. Creating a Swap File :-

To add a swap file:

1. 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 512 MB swap file is 524288 (1024 * 512MB = 524288 block size)

2. Through 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=524288

3. Setup the  linux swap Area/file with the command:-

# mkswap /swapfile

4. To enable the swap file immediately but not automatically at boot time: -

# swapon /swapfile

5. 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.

6. 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 –m

# top

Today I was encountered with one problem,I have successfully install LAMP server on my CentOS 5 box,but when I installed drupal 7.0 on it,it throws an error like the minimum requirement to install the drupal 7.0 is php should be at least 5.2.4 .
These instructions were created using CentOS 5.3 32-bit server :-
First check which version of php you have installed:-

# rpm -qa |grep php

php-mcrypt-5.1.6-15.el5.i386
php-common-5.1.6-15.el5.i386
php-cli-5.1.6-15.el5.i386
php-5.1.6-15.el5.i386
php-pdo-5.1.6-15.el5.i386
php-bcmath-5.1.6-15.el5.i386
php-ldap-5.1.6-15.el5.i386
php-devel-5.1.6-15.el5.i386
php-gd-5.1.6-15.el5.i386
php-xml-5.1.6-15.el5.i386
php-mbstring-5.1.6-15.el5.i386
php-mysql-5.1.6-15.el5.i386
php-dba-5.1.6-15.el5.i386

Add the new repositories:-

First thing we need to do is add the new repositories to yum. When we add the this repository to configure it so it only pulls PHP packages. To start we’ll need create a new yum repository configuration file :
# vi /etc/yum.repos.d/CentOS-Testing.repo
Copy/paste the following into this file:

——————————————————————–

[c5-testing]
name=CentOS-5 Testing
baseurl=http://dev.centos.org/centos/$releasever/testing/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://dev.centos.org/centos/RPM-GPG-KEY-CentOS-testing
includepkgs=php*
———————————————————-

Make sure that there is no spaces at the start of each line, then save and close the file.
Update PHP packages :-
Now you can use yum to update the PHP packages on your system:
# yum update
You should be shown a list of new packages that are going to be updated. Compare it to the list of your previously installed PHP packages . Note any packages that are not in the list. You’ll need to remove these packages or find updates for them because they won’t work after you update to PHP 5.2.x. If that is acceptable type “y” to continue and let yum update the packages.
Once yum has completed restart Apache:
# service httpd restart
To verify the update is working create a simple phpinfo.php in your documentroot or www directory with the following source code:

and open it in a web browser. The new PHP version should be reflected at the top of the page.
Result:-
You should now have PHP 5.2.10 running on CentOS 5.3 32-bit.
# rpm -qa |grep php

php-mcrypt-5.2.9-2.el5.centos.3
php-gd-5.2.10-1.el5.centos
php-devel-5.2.10-1.el5.centos
php-mysql-5.2.10-1.el5.centos
php-pdo-5.2.10-1.el5.centos
php-5.2.10-1.el5.centos
php-xml-5.2.10-1.el5.centos
php-ldap-5.2.10-1.el5.centos
php-common-5.2.10-1.el5.centos
php-cli-5.2.10-1.el5.centos
php-mbstring-5.2.10-1.el5.centos

# php -v

PHP 5.2.10 (cli) (built: Nov 13 2009 11:24:03)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2009 Zend Technologies

Enjoy Linux…!!!

PostgreSQL, often simply Postgres, is an object-relational database management system  (ORDBMS).It is released under an MIT-style license and is thus free and open source software. As with many other open-source programs, PostgreSQL is not controlled by any single company — a global community of developers and companies develops the system.

By default, PostgreSQL database server remote access disabled for security reasons. However, some time you need to provide the remote access to database server from home computer or from web server.

Step # 1: Login to server through ssh :-

Login over ssh to remote PostgreSQL database server:
# ssh user@ip address of the server

Step # 2: Enable client authentication

Once connected, you need edit the PostgreSQL configuration file, edit the PostgreSQL configuration file /var/lib/pgsql/data/pg_hba.conf (or /etc/postgresql/8.4/main/pg_hba.conf for latest 8.4 version) using a text editor such as vi.

Login as postgres user using su / sudo command, enter:
$ su – postgres

PostgreSQL by default refuses all connections it receives from any remote address. You have to relax these rules by adding this line to:-

$ vi /var/lib/pgsql/data/pg_hba.conf

Or

$ vi /etc/postgresql/8.4/main.pg_hba.conf

Append the following configuration lines to give access to 10.10.10.10/24 network :-

Host all all 10.10.10.10/24 trust

You can use your network/mask instead of 0.0.0.0/0 to only allow access from certain Ip address.Save and close the file. Make sure that you replace 10.10.10.10/24 with actual network Ip address range of the clients systemin your own network.

Or

Host all all 0.0.0.0/0 md5

This is an access control rule that lets anyone login from any address if a valid password is provided(the md5 keyword).You can use your network/mask instead of 0.0.0.0/0 to only allow access from certain Ip address

Step # 3: Allow TCP/IP socket

To be able to reach the server remotely you have to add the following line into the file, open PostgreSQL configuration file /var/lib/pgsql/data/postgresql.conf or /etc/postgresql/8.4/main/postgresql.conf.
# vi /etc/postgresql/8.4/main/postgresql.conf
OR
# vi /var/lib/pgsql/data/postgresql.conf
Find configuration line that read as follows:
listen_addresses=’localhost’
Next set IP address(es) to listen on; you can use comma-separated list of addresses; defaults to ‘localhost’, and ‘*’ is all ip address:
listen_addresses=’*’
Or just bind to 220.54.1.2 and 220.54.1.3 IP address
listen_addresses=’220.54.1.2 220.54.1.3′
Save and close the file.

Step # 4: Restart PostgreSQL Server

Type the following command:
# /etc/init.d/postgresql restart

Step # 5: Test your setup

Before test please make sure that your firewall allow the port “5432” default port of postgresql.

Use psql command from client system. Connect to remote server using IP address 10.10.10.50 and login using vivek username and sales database, enter:
$ psql -h 10.10.10.50 -U postgres -d test

Step # 6: Download Postgresql GUI Client

Download any of postgresql GUI client to access databases remotely,one good postgresql gui client is Navicat (www.navicat.com).

Download through :- http://www.navicat.com/en/download/download.html

Enjoy Linux…!!!!

Today after updating my php and apache on the server. I was getting 500 internal error my website and i got below error on my server apache error logs.

“/usr/bin/php: symbol lookup error: /usr/local/lib/php/extensions/no-debug-non-zts-20060613/suhosin.so: undefined symbol: zend_atol”

The error message appears when an old application or software is upgraded to latest version. It may not cause issues with all the applications but definitely does affect some of them.

The only works when you enable suhosin.simulation for the account instead of disabling suhosin on the server.

You can perform this task by following ways :-

1. By enabling suhosin.simulation in .htaccess file. If susphp is not enabled on the server.

php_flag suhosin.simulation On

2. By creating php.ini file under public_html/ directory. If susphp is enabled on the server.

suhosin.simulation On

If you are getting same error under wp-admin login page then copy your php.ini file under wp-admin/ directory and check once again.

Now you can check your application, Also there is no need to restart any service like apache….It will work…!!!

Solution :- Just login to your Server with root user and do the following changes in your ftp configuration :-

1. Open the main ftp configuration file.
2. root@linuxdude[~]# vi /etc/pure-ftpd.conf
3. Just check the line no. 164 :-

——————————————————————–

# ‘ls’ recursion limits. The first argument is the maximum number of
# files to be displayed. The second one is the max subdirectories depth

LimitRecursion 2000 8
——————————————————————–

4. edit /etc/pure-ftpd.conf and change line 164 to:

# ‘ls’ recursion limits. The first argument is the maximum number of
# files to be displayed. The second one is the max subdirectories depth

LimitRecursion 5000 15

5.Just save the file after modification and restart the pureftp server with the following command :-

root@linuxdude[~]# /etc/init.d/pure-ftpd restart

Now you can upload total 5000 files through ftp and 15 parallel subdirectories are allowed.

Enjoy Linux..

The Linux kernel includes full PAE mode support starting with version 2.3.23, enabling access of up to 64 GB of memory on 32-bit machines. A PAE-enabled Linux-kernel requires that the CPU also support PAE.

How to update/install the PAE kernel :-

1. Please check either PAE kernel install on your server or not :-

# rpm -qa kernel\* | sort or
# rpm -qa |grep PAE or
# Uname -r

2. Chek the available PAE kernel inforamtion :-

# yum info kernel-PAE

Available Packages
Name : kernel-PAE

Summary: The Linux kernel compiled for PAE capable machines.

Description:
This package includes a version of the Linux kernel with support for up to
64GB of high memory. It requires a CPU with Physical Address Extensions (PAE).

The non-PAE kernel can only address up to 4GB of memory.

Install the kernel-PAE package if your machine has more than 4GB of memory.

3. Install the kernel-PAE package :-

# yum install kernel-PAE

4. Once the install has finished, take a look at which kernels are now installed on your system (rpm -qa kernel\* | sort ), confirm that the PAE kernel will be the default on system boot (less /etc/grub.config – make sure that the PAE kernel is the first in the list of kernels to be referenced), ensure that all future updates will be of the PAE kernel (edit the file /etc/sysconfig/kernel so that the bottom line now reads DEFAULTKERNEL=kernel-PAE rather than DEFAULTKERNEL=kernel) and then reboot the system.

5. just change the contents of the file /etc/sysconfig/kernel to be:

# UPDATEDEFAULT specifies if new-kernel-pkg should make
# new kernels the default
UPDATEDEFAULT=yes

# DEFAULTKERNEL specifies the default kernel package type
DEFAULTKERNEL=kernel-PAE

6. for consistency, you might as well yum install kernel-PAE-devel

7. Here is /etc/grub.conf contains :-

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/sda5
# initrd /initrd-version.img
#boot=/dev/sda
default=1
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.18-53.1.14.el5PAE)
root (hd0,0)
kernel /vmlinuz-2.6.18-53.1.14.el5PAE ro root=LABEL=/
initrd /initrd-2.6.18-53.1.14.el5PAE.img
title CentOS (2.6.18-8.el5)
root (hd0,0)
kernel /vmlinuz-2.6.18-8.el5 ro root=LABEL=/
initrd /initrd-2.6.18-8.el5.img

Note :- ‘Default’ starts at 0, not 1.So you have to change “default=1 to default=0.

Once your system has rebooted, your system will be running with PAE kernel, check the kernel with uname -rmi and by using the command free -om, check that all your memory is now visible.

Enjoy Linux..!!!!

SUSE Linux is your opensource operating system

Apache2 is the master webserver on the planet

MySQL is your favorite opensource database

PHP is the popular web programming language

The easiest way to get the LAMP server installed would be to install LAMP from the YaST GUI as follows:

1.LAMP Installation from YaST :

I prefer the manual option to setup a LAMP Server.

So without wasting much of time, lets proceed to get LAMP up and running on your openSUSE in no time. I’m using openSUSE 11.0 but the procedure should equally work on earlier 10.3 and other 10.2 versions.

2.Install & Configure Apache2 Webserver :

Install Apache webserver

opensuse11:~ # yast2 –install apache2

This should install apache webserver. To check try the following command:

opensuse11:~ # rcapache2 status

Checking for httpd2:                                          unused

That tells you, the Apache webserver is installed but just not started yet.

To test if the webserver serves pages, add a file index.html into /srv/www/htdocs/ directory. This is the default web root directory for apache on your system.

opensuse11@ p-root # cd /srv/www/htdocs

opensuse11@ p-root # vi index.html

and enter some text say “Welcome to openSUSE 11.0”

Start Apache2 Webserver

Now start the Apache 2 webserver so we can check if it works OK.

opensuse11@ p-root # rcapache2 start

Starting httpd2 (prefork)                                         done

Now, open a web browser like Firefox and go to http://localhost and you should see the ext you entered (here “Welcome to openSUSE 11.0?)

3.Let’s proceed to install PHP5 :

Install PHP5

opensuse11@ p-root # yast2 –install php5 php5-mysql apache2-mod_php5

This should install PHP5, PHP5-MySQL module and the Apache2 PHP5 module.

For Apache2 to enable the PHP5 module, restart for changes to take effect.

opensuse11@ p-root# rcapache2 restart

Syntax OK

Shutting down httpd2 (waiting for all children to terminate)          done

Starting httpd2 (prefork)                                                          done

4.Install & configure MySQL :

opensuse11@ p-root # yast2 –install mysql mysql-tools

This should install MySQL Database Server and options mysql-tools (for administration) on your openSUSE. To check the installation, run the following command:

opensuse11@ p-root # rcmysql status

Checking for service MySQL:                                           unused

The above indicates that the MySQL Server is installed but not started yet.

Start MySQL Server

opensuse11@ p-root# rcmysql start

Starting service MySQL                                                done

By default there is no root password set for MySQL and it is important to set the password for the ROOT account.

Set Root Password

opensuse11@ p-root # mysqladmin -u root -p rootpassword

This should set the root password as “rootpassword”. Set the password to something more appropriate.

To check if Root password is set and the MySQL Client can logon to the MySQL Server try the following:

opensuse11@ p-root # mysql -u root -p

Enter password: ********

Welcome to the MySQL monitor.  Commands end with ; or g.

Your MySQL connection id is 1

Server version: 5.0.51a SUSE MySQL RPM

Type ‘help;’ or ‘h’ for help. Type ‘c’ to clear the buffer.

mysql> show databases;

+——————–+

| Database           |

+——————–+

| information_schema |

| mysql              |

| test               |

+——————–+

3 rows in set (0.04 sec)

mysql>

In the above, I used mysql client to logon as root, entered the password and list the databases. That completes the installation of LAMP on openSUSE 11.0

To administer MySQL database, the easiest and the popular tool is phpMyAdmin, given that we have discussed PHP5, apache2 setup here which are required for phpMyAdmin, it makes sense to look at quickly setting up and configure phpMyAdmin

5.Install phpMyAdmin :

opensuse11@ p-root # yast2 –install phpMyAdmin

This installs phpMyAdmin and setup a website at /srv/www/htdocs/phpMyAdmin directory. Change directory and use the sample config file to quickly setup phpMyAdmin.

opensuse11@ p-root # cd /srv/www/htdocs/phpMyAdmin

opensuse11@ p-root # cp config.sample.inc.php config.inc.php

Edit the file and look for

$cfg['blowfish_secret'] = ‘mysqladmin’;

Enter a value for blowfish secret (I’ve set it to mysqladmin here)

Thats done and has the default configs on it. Logon to phpMyAdmin from http://localhost/phpMyAdmin with the MySQL root username and password.

p-root

Enjoy Linux