mysql.sock is required for mysqld processes to operate. For example, if your mysql.sock file exists in /tmp and you decide to delete all the 'temp files' you will have a problem with mysql
You should make sure you know which directory that the mysql.sock file is created and make sure the mysqld processes have permission to write to that directory... and make sure that prior mysql.sock files are either deleted or have correct permissions so when another process is started it can overwrite this file.
For example:
Quote:
server# cd /tmp
server# ll *sock*
srwxrwxrwx 1 root root 0 Aug 10 00:14 mysql.sock=
server#
Notice that the mysql.sock file is in /tmp and the permission are root.root because mysql is running as root.root. If you are not running mysql as root, then you could have problems writing if another mysql.sock file exists, etc.
My advise is to find out where your system is writing this file, shutdown mysql, delete all the old mysql.sock files, check permissions and restart.