The yum system does not require any routine maintenance. To ensure that yum operations are carried out at optimal speed, disable or remove repository definitions which you no longer require. You may also clear the files from the yum caches in order to recover disk space.
Set enable=0 in a definition file to prevent yum from using that repository. The yum utility ignores any definition file with this setting.
To completely remove access to a repository:
Delete the relevant file from /etc/yum.repos.d/.
Delete the cache directory from /var/cache/yum/.
By default, yum retains the packages and package data files that it downloads, so they may be reused in future operations without being downloaded again. To purge the package data files, use this command:
su -c 'yum clean headers'
Run this command to remove all of the packages held in the caches:
su -c 'yum clean packages'
When using these commands, at the prompt, enter the password for the root account.
Purging cached files causes those files to downloaded again the next time that they are required. This increases the amount of time required to complete the operation.