I just upgraded from mysql 3.23.51 to 4.0.3 and mysql refuses to start. I found that mysql.sock file has vanished from the system!! I have looked at all places, but can't find it. Where can I find a copy of the file and download/reinstall it? I have tried reinstalling the .rpm packages (I am on RH 7.2) but the file did not show up. Please help!