centos cache

We need to clean the YUM cache to reclaim the disk space used or to fix some errors due to corrupted metadata files.

Clean all the cached packages from the enabled repository cache directory.
```
yum clean packages
```
Delete package headers.
```
yum clean headers
```
Delete metadata for each enabled repository.
```
yum clean metadata
```
```
Clean database cache

yum clean dbcache
```

Clean expire cache

yum clean expire-cache

Done!