HowTo: Update Centos Linux 5.4 to 5.5

Step # 1: Make A Backup

It cannot be stressed enough how important it is to make a backup of your system before you do this. Use the following tools to backup data to other server or USB hard disk:

• Use mysqldump for MySQL databases
• Use pg_dump for PostgreSQL databases
• Use tar and rsync tool for LAMP

Step # 2: Update All Packages

Type the following command to get a list of packages that are going to be updated, enter:
# yum list updates
To upgrade your box, enter:
# yum update

Fig.01: CentOS Upgrade In Progress Over The SSH Session

Reboot the server:
# reboot

Verify everything is working:
# uname -a
# netstat -tulpn
# tail -f /var/log/messages
# tail -f /path/to/log/file
# cat /etc/redhat-release
Sample outputs:

CentOS release 5.5 (Final)

You can use the the lsb_release command as follows:
# lsb_release -a
Sample outputs:

LSB Version:	:core-3.1-amd64:core-3.1-ia32:core-3.1-noarch:graphics-3.1-amd64:graphics-3.1-ia32:graphics-3.1-noarch
Distributor ID:	CentOS
Description:	CentOS release 5.5 (Final)
Release:	5.5
Codename:	Final

To view log of all updated package, enter:

tail -f /var/log/yum.log
less /var/log/yum.log
grep -i httpd /var/log/yum.log

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