執行yum list時出錯解決

問題：
hi when i try to do a search with yum i get this error.

Error: Caching enabled and local cache: //var/cache/yum/base/primary.xml.gz does not match checksum

i don't know much about programming yet so i don't know what a checksum is for sure. What does this error mean and is it something that would be hard to fix? thanks for any replies in advance.
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解決辦法:
   
I'm not sure it's applicable in FC2, but you might be able to rebuild yum's cache by

$ yum makecache