Openvz installation

1 Installing OpenVZ
In order to install OpenVZ, we need to add the OpenVZ repository to yum:
cd /etc/yum.repos.d

wget http://download.openvz.org/openvz.repo
rpm --import http://download.openvz.org/RPM-GPG-Key-OpenVZ

yum search ovzkernel
yum install ovzkernel
then place the openvz kerel in the first position of the grub.conf file

title CentOS OpenVZ (2.6.18-53.1.19.el5.028stab053.14)
root (hd0,0)
kernel /vmlinuz-2.6.18-53.1.19.el5.028stab053.14 ro root=/dev/VolGroup00/LogVol00
initrd /initrd-2.6.18-53.1.19.el5.028stab053.14.img

Install vps utilities
for 32 bit
yum install vzctl vzquota

for 64 bit
yum install vzctl.x86_64 vzquota.x86_64

Open /etc/sysctl.conf and make sure that you have the following settings in it:
[...]
net.ipv4.ip_forward = 1
net.ipv4.conf.default.proxy_arp = 0
net.ipv4.conf.all.rp_filter = 1
kernel.sysrq = 1
net.ipv4.conf.default.send_redirects = 1
net.ipv4.conf.all.send_redirects = 0
net.ipv4.icmp_echo_ignore_broadcasts=1
net.ipv4.conf.default.forwarding=1
[...]

If you need to modify /etc/sysctl.conf, run
sysctl -p

The following step is important if the IP addresses of your virtual machines are from a different subnet than the host system's IP address. If you don't do this, networking will not work in the virtual machines!

Open /etc/vz/vz.conf and set NEIGHBOUR_DEVS to all:
NEIGHBOUR_DEVS=all

SELinux needs to be disabled if you want to use OpenVZ. Open /etc/sysconfig/selinux and set the value of SELINUX to disabled:
vi /etc/sysconfig/selinux
OR
vi /etc/selinux/config

SELINUX=disabled
# SELINUXTYPE= type of policy in use. Possible values are:
# targeted - Only targeted network daemons are protected.
# strict - Full SELinux protection.
SELINUXTYPE=targeted

then reboot

Procedure To Add a Swap File

You need to use the dd command to create swap file. The mkswap command is used to set up a Linux swap area on a device or in a file.

a) Login as the root user.

b) Type following command to create 512MB swap file (1024 * 512MB = 524288 block size):
# dd if=/dev/zero of=/swapfile1 bs=1024 count=524288

c) Set up a Linux swap area:
# mkswap /swapfile1

d) Activate /swapfile1 swap space immediately:
# swapon /swapfile1

e) To activate /swapfile1 after Linux system reboot, add entry to /etc/fstab file. Open this file using a text editor such as vi:
# vi /etc/fstab

Append the following line:
/swapfile1 swap swap defaults 0 0

So next time Linux comes up after reboot, it enables the new swap file for you automatically.

g) How do I verify swap is activated or not?
Simply use the free command:
$ free -m

* How to replace Apache with Lighttpd on Cpanel

Lighttpd is another free webserver that is becoming more popular due to it's performance boosts over Apache and thus improving the overall server performance. This guide will show you how it's possible to replace Apache with Lighttpd while running CPanel.

Things to do prior to making the switch:

1. Make sure to recompile Apache with fastcgi support. This can be done via WHM --> Apache Configuration.
2. This setup is better for servers with a few large sites than a host with many smaller sites as a Shared host would have. If Apache is working fine, there is no need to do this.
3. If you need to have sites with SSL enabled, it will be a little trickier and will not be covered in this how-to. You can reference this link for more details:
http://redmine.lighttpd.net/wiki/1/DocsSL
4. When creating accounts after making the switch to Lighttpd, you will still use the Create Account feature, but since httpd will not be running, you will have to manually add the virtual host details to the lighttpd.conf file or hosts.conf as we will have in this example.

Step 1

Download and compile Lighttpd:

1. First get the source from www.lighttpd.net and follow the instructions there.
2. To configure: ./configure --with-openssl --with-zlib --with-bzip2 --with-memcache
NOTE: may need to install pcre-devel (yum install pcre-devel)
3. Follow the instructions here to get lighttpd configured after the install: http://redmine.lighttpd.net/projects...tallFromSource You may need to change the path in /etc/init.d/lighttpd file to /usr/local/sbin/lighttpd for it to start.
4. Configure the lighttpd.conf file in /etc/lighttpd/. Example of a working lighttpd.conf:
Code:

server.modules = ( "mod_fastcgi", "mod_rewrite", "mod_dirlisting", "mod_auth", "mod_setenv", "mod_status" )
server.document-root = "/usr/local/apache/htdocs"
server.errorlog = "/etc/lighttpd/error.log"
server.username = "nobody"
server.groupname = "nobody"
index-file.names = ( "index.html", "index.htm", "index.php" )
server.tag = "Web Services"
status.status-url = "/lighttpd-status"
static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" )
server.port = 80
include "includes/mime.conf"
include "includes/optimizations.conf"
include "includes/php.conf"
include "includes/hosts.conf"

You can get the server.document-root from the existing httpd.conf file for Apache for the main VirtualHost.
5. In the /etc/lighttpd directory, create the includes directory:
Code:

mkdir includes

and create the mime.conf, optimizations.conf, php.conf and hosts.conf files in the includes directory. Chmod them to 644:
Code:

chmod -R 644 includes

run this command within the /etc/lighttpd directory.
6. Now we need to populate the created conf files that lighttpd will load upon startup.

mime.conf:
Code:

mimetype.assign = (
".pdf" => "application/pdf",
".sig" => "application/pgp-signature",
".spl" => "application/futuresplash",
".class" => "application/octet-stream",
".ps" => "application/postscript",
".torrent" => "application/x-bittorrent",
".dvi" => "application/x-dvi",
".gz" => "application/x-gzip",
".pac" => "application/x-ns-proxy-autoconfig",
".swf" => "application/x-shockwave-flash",
".tar.gz" => "application/x-tgz",
".tgz" => "application/x-tgz",
".tar" => "application/x-tar",
".zip" => "application/zip",
".mp3" => "audio/mpeg",
".m3u" => "audio/x-mpegurl",
".wma" => "audio/x-ms-wma",
".wax" => "audio/x-ms-wax",
".ogg" => "application/ogg",
".wav" => "audio/x-wav",
".gif" => "image/gif",
".jpg" => "image/jpeg",
".jpeg" => "image/jpeg",
".png" => "image/png",
".xbm" => "image/x-xbitmap",
".xpm" => "image/x-xpixmap",
".xwd" => "image/x-xwindowdump",
".css" => "text/css",
".html" => "text/html",
".htm" => "text/html",
".js" => "text/javascript",
".asc" => "text/plain",
".c" => "text/plain",
".cpp" => "text/plain",
".log" => "text/plain",
".conf" => "text/plain",
".text" => "text/plain",
".txt" => "text/plain",
".dtd" => "text/xml",
".xml" => "text/xml",
".mpeg" => "video/mpeg",
".mpg" => "video/mpeg",
".mov" => "video/quicktime",
".qt" => "video/quicktime",
".avi" => "video/x-msvideo",
".asf" => "video/x-ms-asf",
".asx" => "video/x-ms-asf",
".wmv" => "video/x-ms-wmv",
".bz2" => "application/x-bzip",
".tbz" => "application/x-bzip-compressed-tar",
".tar.bz2" => "application/x-bzip-compressed-tar",
"" => "application/octet-stream"
)

optimizations.conf:
Code:

server.event-handler = "linux-sysepoll"
server.max-fds = 32768
server.network-backend = "linux-sendfile"
server.max-connections = 8192
server.max-keep-alive-requests = 15
server.max-keep-alive-idle = 15
server.max-read-idle = 15
server.max-write-idle = 15
server.max-worker = 1

The 'server.max-worker' variable should be changed according to how many CPUs the server has, and if it's a 64bit system. If it's a 32bit system, and the load stays low, keep it at 1. To get rid of keep-alive, set both of the keep-alive lines to 0. Max connections can be alterted to your needs

php.conf:
Code:

fastcgi.server = ( ".php" =>
( "localhost" =>
(
"socket" => "/tmp/php-fastcgi.socket-" + var.PID,
"bin-path" => "/usr/bin/php-cgi",
"max-procs" => 20,
"idle-timeout" => 10,
"bin-environment" => (
"PHP_FCGI_CHILDREN" => "20",
"PHP_FCGI_MAX_REQUESTS" => "500" ),
)
)
)

To get the bin-path, just run
Code:

whereis php-cgi

and that will show you the path. You have to compile Apache with fastcgi support first via WHM as mentioned previously. PHP can run as DSO/CLI still via WHM.

hosts.conf:
Code:

$HTTP["host"] =~ "^(www\.|)domain\.com$" {
server.document-root = "/home/domain/public_html/"
}

$HTTP["host"] =~ "^(www\.|)domain2\.com$" {
server.document-root = "/home/domain2/public_html/"
}

Adjust this file to your needs. Look at your Apache's httpd.conf file and setup each vhost using the above templates for each domain/subdomain you have in httpd.conf. If you wish to add logs to each domain, you can add the following lines to each one of the vhosts above between the {} brackets:
Code:

server.errorlog = "/var/log/lighttpd/domain/error.log"
accesslog.filename = "/var/log/lighttpd/domain/access.log"
server.error-handler-404= "/e404.php"

Now you should be all done with the main lighttpd configuration, so go ahead and turn it on:
Code:

/etc/init.d/lighttpd start

7. Now we need to turn off Apache so it does not start on boot or start by Cpanel. To do this, login to WHM and go to Service Manager, then uncheck both of the boxes for httpd. You can also run the following command to turn it off via shell:
Code:

chkconfig httpd off

This will ensure Apache won't start.

At this point, you should be running completely on lighttpd. Everything else in Cpanel/WHM will work as usual (mysql, dns, email, etc..). If you need to recompile php, you can do so via Apache Configuration, just be sure to turn off Apache again after you recompile.

source: http://forums.ayksolutions.com/showthread.php?p=829

How to backup your linux VPS.

Backup script for vps

#!/bin/sh
####################################
#
# Backup to NFS mount script.
#
####################################

# What to backup.
backup_files="/"

# Where to backup to.
dest="/home/backup"

# Create archive filename.
day=$(date +%A)
hostname=$(hostname -s)
archive_file="$hostname-$day.tgz"

# Print start status message.
echo "Backing up $backup_files to $dest/$archive_file"
date
echo

# Backup the files using tar.
tar czf $dest/$archive_file $backup_files

# Print end status message.
echo
echo "Backup finished"
date

# Long listing of files in $dest to check file sizes.
ls -lh $dest

enable php function

1. Remove all functions from disable_functions in php.ini
2. Add functions in php.ini suhosin.executor.func.blacklist = “” those you want to disable globally.

After that in the virtual host section of a domain you can add below code to enable a function only for one domain:


………..

php_admin_value suhosin.executor.func.blacklist = “shell_exec”

……


In this example shell_exec has been enabled for the VirtualHost.

PS:virtual host settings will work only if suhosin is installed in the server

Install nginx

Login to SSH and do this

cd /usr/local/src
wget http://nginxcp.com/latest/nginxadmin.tar
tar xf nginxadmin.tar
cd publicnginx
./pythonfix
./nginxinstaller install

It's Done...... Now go to WHM and search for nginx, You will see it there

are you getting "502 Bad Gateway" error ?

here is the solution

go to WHM and search for "tweak settings"

open it and search for "Apache non-SSL" and set it to "0.0.0.0:8081"

mass upload bash script (good for Megaupload)

#!/bin/bash

ftp -inv << FTP
open ftp.eu.filesonic.com
user USERNAME PASSWORD
lcd /YOUR/FOLDER/WITH/FILES
mput *.zip
bye
FTP