Originally Posted by ondemandemails
i tried to use yum to upgrade the squid but it said yum is already locked by other process.
Irrespective of the squid part of the question, you will need to fix yum anyway. You have probably started something else which has locked the rpm database. Do you know what that might be?
If not, is there a possibility that something working with the database crashed and left a lock file?
Please conduct the conversation here; anything else is not helping the community, and is not something that I, for one, will help with.