Install xen virtual server on linux platform

Before installing xen on the linux (centos or Redhat), please check the compatiblity. Then check whether the server has already installed xen. There packages should be checked. I checked using RPM.

.1 xenserver# rpm -qa |grep xen
xen-libs-3.1.0-13.el5
xen-3.1.0-13.el5
xenserver #rpm -qa |grep kernel-xen
kernel-xen-2.6.21-2950.el5
xenserver-dev #rpm –qa |fgrep virt-manager //for GUI
virt-manager-0.5.2-2.el5

Install :
1.
xenserver# yum install xen
xenserver # yum install kernel-xen
xenserver # yum install virt-manager

2. Edit default=1 in /boot/grub/grub.conf and make sure xen kernel will load.
3. Reboot system : [root@xenserver]# init 6
4. check kernel :
[root@xenserver]# uname -r
2.6.21-2950.el5xen
=====
To check if Xen is running use xm from command line:
[root@xensever]# xm list
Now you can create Xen virtual machines using Xen command lines or xen GUI (virt-manager):

[xenserver@ldev ~]# virt-manager

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What is Ruby on Rails? Install on linux plat form

What is Ruby on Rails?

Ruby is a programming language just like Perl, Python or PHP. Rails is an open source Ruby framework for developing database-backed web applications. You could develop a web application at least ten times faster with Rails than you could with a typical Java framework. It is a web application framework written in the Ruby programming language.



We tried the installation of Ruby on Rails on a server with this configuration:

1. Red Hat Linux release 7.3

2. Plesk 5.0.5

3. Apache 1.3.27

4. PHP 4.3.4 # Run as an Apache Module

Install Ruby

Before installing Ruby, first check if zlib is installed in PHP. You can do this by running a simple script with this code.



Now you are all set to start the installation.

cd /usr/local/src

wget ftp://ftp.ruby-lang.org/pub/ruby/ruby-1.8.2.tar.gz

tar xvzf ruby-1.8.2.tar.gz

cd ruby-1.8.2

./configure

make

make install

ruby rubytest.rb

If the installaiton is successful, then you will get a message “test succeeded”.

Install RubyGems

cd /usr/local/src

wget http://rubyforge.org/frs/download.php/5207/rubygems-0.8.11.tgz

tar xvzf rubygems-0.8.11.tgz

cd rubygems-0.8.11

ruby setup.rb all

This step involves execution of `ruby setup.rb` with arguments `config / setup / install` all together

gem query --local

OR

gem q -L

Listing all installed gems

Install Rails

gem install rails OR # (Enter Y for all dependencies)

gem install rails --include-dependencies

Install FastCGI

wget http://fastcgi.com/dist/fcgi-2.4.0.tar.gz

tar -xvzf fcgi-2.4.0.tar.gz

cd fcgi-2.4.0

./configure

make

make install

Install mod_fastcgi

wget http://www.fastcgi.com/dist/mod_fastcgi-2.4.2.tar.gz

tar -xvzf mod_fastcgi-2.4.2.tar.gz

cd mod_fastcgi-2.4.2

/path/to/apxs -o mod_fastcgi.so -c *.c

/path/to/apxs -i -a -n fastcgi mod_fastcgi.so

In Apache’s httpd.conf, add this line.

Include /path/to/httpd/conf/fastcgi.conf

Now, add this text to fastcgi.conf

cat > /path/to/httpd/conf/fastcgi.conf

User apache

Group apache



FastCgiConfig -idle-timeout 900

AddHandler fastcgi-script .fcgi .fpl .rb

FastCgiIpcDir /tmp/fastcgi_ipc/

FastCgiSuexec /usr/sbin/suexec

To make FastCGI run as suexec. Use path to suexec





Ctrl + D

mkdir /tmp/fastcgi_ipc/

chown -R apache.apache /tmp/fastcgi_ipc

chmod 700 /tmp/fastcgi_ipc/

service httpd restart

NOTE : In some systems, the ownership of fastcgi_ipc is done by Apache itself, but its safe to include these steps in your routine.

Related files: /usr/local/lib/ruby/gems/1.8/gems/rails-1.0.0/dispatches/dispatch.fcgi # OR ~USER//public/dispatch.fcgi # Log file declaration & all

Install gem bindings

To install gem bindings for Fastcgi and MySQL

gem install fcgi

gem install mysql

Testing

1. Install Test Application

cd ~USER

rails testapp # Create a test application named 'testapp'

cd testapp/

./script/generate controller test

cd ~USER/httpdocs

ln -s ~USER/testapp/public rails

# In order to access the test application

'~USER/testapp/public' from the browser

In order to allow symlinks, enter the following in to ~USER/httpdocs/.htaccess

Options Indexes +FollowSymLinks

Now you need to set the correct ownership and permissions for the test application. I did the following for my project. You can learn from the example:

cd ~USER

chown -R USER.psacln testapp

chmod -R 755 testapp

chown -R USER.psacln httpdocs/rails

chmod -R 755 httpdocs/rails

Create Test Pages

cd ~USER

cd ~USER/testapp/app/controllers

Create a file called test_controller.rb and put in the following code:

cat > test_controller.rb

class TestController < ApplicationController

def hi

render :text => 'Hi world'

end

def hello

end

def index

render :text => 'Hi! This is the Index.'

end

end

Ctrl + D

Now create the test page.

cat > ~USER/testapp/app/views/test/hello.rhtml # The test page

Hello from Rails!

The current time is <%= Time.now %>

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Various linux commands

grep -irl saqun.com * [i=case sensitive,allow both case. r=recursive, l=list out] // search domain in /hsphere/local/config/httpd/sites/

1.check php version: php -v

2.check which php: php -i // php -i |grep php.ini

3./usr/local/cpanel/logs // logs of cpanel

4./var/cpanel/userdata // gives the user data.

5.ctrl+] // to come out from established connection

Then q enter.

7.Search customer by name or by email id:-

8.vps # vzctl enter (id of domain) // to go to root of particular domain.

9.For neural customer search from database the details. Take user & password and login from www.emcwebhosting.com site.

10.cd /dir && command

11.ls /etc | pr -T9 -W$COLUMNS // print contents in 9 columns.pr=print T9=9 column W=width.

12.find -name '*.[ch]' | xargs grep -E 'expr' //Search 'expr' in this dir and below. See also findrepo

13.find -type f -print0 | xargs -r0 grep -F 'example' //Search all regular files for 'example' in this dir and below

14.find -maxdepth 1 -type f | xargs grep -F 'example' //Search all regular files for 'example' in this dir

15.find -type f ! -perm -444 ///Find files not readable by all (useful for web site)

16.find -type d ! -perm -111 //Find dirs not accessible by all (useful for web site)

17.grep --color kamal /etc/passwd //Highlight occurances of regular expression in dictionary

18. gpg -c file //Encrypt file

gpg file.gpg //Decrypt file

19. scp -p -r $USER@$HOST: file dir/ // Copy with permissions to $USER's home directory on $HOST

20.ssh -g -L 8080:localhost:80 root@$HOST //Forward connections to $HOSTNAME:8080 out to $HOST:80

ssh -R 1434:imap:143 root@$HOST //Forward connections from $HOST:1434 in to imap:143

21.

wget -c http://www.example.com/large.file //Continue downloading a partially downloaded file

wget -r -nd -np -l1 -A '*.jpg' http://www.example.com/dir/ //Download a set of files to the current directory

22.

echo 'wget url' | at 01:00 //Download url at 1AM to current dir

wget --limit-rate=20k url //Do a low priority download (limit to 20KB/s in this case)

wget -o log url // faults r stored in log file . log=/x.txt

wget --dns-timeout=seconds url

--connect-timeout=seconds url

--read-timeout=seconds url

--limit-rate=amount url

--user=user url

--password=password url

23. ethtool eth1 // show status of ethernate 0 1

24.ip link show //List network interfaces

25.

ethtool eth0 //Show status of ethernet interface eth0

ethtool --change eth0 autoneg off speed 100 duplex full //Manually set ethernet interface speed

iwconfig eth1 //Show status of wireless interface eth1

iwconfig eth1 rate 1Mb/s fixed //Manually set wireless interface speed

iwlist scan //List wireless networks in range

ip link set dev eth0 name wan //Rename interface eth0 to wan

ip link set dev eth0 up //Bring interface eth0 up (or down)

ip addr show //List addresses for interfaces

ip addr add 1.2.3.4/24 brd + dev eth0 //Add (or del) ip and mask (255.255.255.0)

ip route show //List routing table

ip route add default via 1.2.3.254 //Set default gateway to 1.2.3.254

26.

netstat -tupl //List internet services on a system with it we can search anything by grep

netstat -tup //List active connections to/from system

27.

cal -3 // Display a calendar

cal 9 1752 // Display a calendar for a particular month year

date -d fri //What date is it this friday. See also day

28. ls -lSr ls -lS // show the file order in size.

29. df -h Show free space on mounted filesystems

• df -i Show free inodes on mounted filesystems

• fdisk -l Show disks partitions sizes and types (run as root)

30.lsof -p $$ //List paths that process id has open

tcpdump not port 22 //Show network traffic except ssh. See also tcpdump_not_me

ps -e -o pid,args --forest //List processes in a hierarchy

ps -p 1,2 //List info for particular process

watch -n.1 'cat /proc/interrupts' // Watch changeable data continuously IDs

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

31.• uname -a //Show kernel version and system architecture

• head -n1 /etc/issue //Show name and version of distribution

• cat /proc/partitions //Show all partitions registered on the system

• grep MemTotal /proc/meminfo //Show RAM total seen by the system

• grep "model name" /proc/cpuinfo //Show CPU(s) info

• lspci -tv //Show PCI info

• lsusb -tv //Show USB info

• mount | column -t //List mounted filesystems on the system (and align output)

• grep -F capacity: /proc/acpi/battery/BAT0/info // Show state of cells in laptop battery

# dmidecode -q | less //Display SMBIOS/DMI information

# smartctl -A /dev/sda | grep Power_On_Hours //How long has this disk (system) been powered on in total

# hdparm -i /dev/sda //Show info about disk sda

# hdparm -tT /dev/sda //Do a read speed test on disk sda

# badblocks -s /dev/sda

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

32. pg

Used to display data one page (screenful) at a time. The command can take a number of filenames as arguments.

Pg [option] [filename] [filename2]…..

33.sort

Sort is a utility program that can be used to sort text files in numeric or alphabetical order

Sort [filename]

34.& - run a program in background mode.

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

35. Get back windows admin password: "C:\Program Files\SWsoft\Plesk\admin\bin\plesksrvclient.exe" –get

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