Roll back packages on Linux:

RHEL 5 preferably uses yum as the program to update, install and remove packages.
When you have installed/updates packages with yum or rpm, you can quite easily roll back the updates/installations using rpm.
For this, yum and rpm need to save roll back information, which they do not do by default.
To enable the roll back feature, do the following:
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Add tsflags=repackage to /etc/yum.conf.
Add %_repackage_all_erasures 1 to /etc/rpm/macros. If /etc/rpm/macros does not exist, just create it.
You can now install, erase and update packages with yum and/or rpm, and they will save roll back information.
When you want to roll back, use rpm to do so.
You do this by specifying the --rollback switch and a date/time, like the examples below:
rpm -Uhv --rollback '19:00'
rpm -Uhv --rollback '8 hours ago'
rpm -Uhv --rollback 'february 09'
rpm -Uhv --rollback 'yesterday'