Preventing packages from update may be needed sometimes. This task varies from distro to distro, actually from package manager to package manager.

This is how you prevent packages from update, on Debian, Ubuntu, Linux Mint, Knoppix, and other debian based distros:
# echo “packagename hold” | dpkg --set-selections
Example:
# echo “ruby1.8 hold” | dpkg --set-selections
To do the same thing on Fedora and CentOS, this is what you have to do.
As root append the following in the /etc/yum.conf file:
[main]
exclude = package1 package2 package99
Replace packagename1 package2 package99 with the name of the packages you want to prevent from update.
Example:
[main]
exclude = ruby1.8 octave 3.2