For some operations (for example, a yum install operation), Yum downloads the packages to install into the Yum cache. The cached packages are located in a subdirectory structure from /var/cache/yum that reflects the architecture, the distribution release, and the repository from where the packages were downloaded.
After successful installation, the packages are deleted from the cache. To retain the cached packages, change the keepcache setting to 1 in the /etc/yum.conf file as follows:
# vi /etc/yum.conf keepcache = 1
Cleaning the Yum Cache
Clean the Yum cache to reclaim disk space or to clear errors due to corrupted metadata files. To remove cached packages only, use:
# yum clean packages
To delete metadata for each enabled repository, use the following command:
# yum clean metadata
To delete package headers, use the following command:
# yum clean headers
To clean all cached information, use the following command:
# yum clean all
If you get the message “Metadata file does not match checksum” during a Yum operation, clearing the metadata from the cache might not help. In this case, adding the following line to /etc/yum.conf resolves the problem:
# vi /etc/yum.conf http_caching=none
Changing default location of yum cache
Sometimes when the default yum cache location is full, you would get an error while installing any yum package.
insufficient space in download directory /var/cache/yum/rhel-x86_64-server-6/packages
As the /var filesystem where yum cache is located is full and there is no disk space for yum to download the system updates, the above error will be shown.
The yum cache location is configured in /etc/yum.conf file as cachedir option in the [main] section and can be changed:
$ cat /etc/yum.conf [main] cachedir=/var/cache/yum/$basearch/$releasever