Step by Step method to upgrade RHEL5 to RHEL6

First on current RHEL5 backup the list of packages installed just in case if you want to cross verify.

rpm -qa --queryformat "%{NAME}\n" | sort > /root/all_old_packages

Check Selinux is enabled or not if enable disable it and uninstall it .

command used is


SELinux status:                 disabled  ( in my case it is disabled )
 vi /etc/inittab change to runlevel 3

id:3:initdefault:  ( mine is a server which is already in runlevel 3 )


remove old docs

rm -rf /usr/share/doc/HTML/*/docs/common ( this is mandatory else upgrade will fail)


Now boot with RHEL6 DVD on boot menu press esc

then enter " linux upgradeany "

Follow instructions and you are done . IF you face any issues you can got to other run levels and check what caused failure. You can troubleshoot that issue and upgrade. During my installation i faced only one issue . That is the reason i have deleted old documents.