I have a problem that my linux is working as a server but setup some web site at these server need to define the username and password of the mysql and I don't know them so what can I do ?!note that mysql is running at the linux service thanks
By the sound of it you have not setup the mysql password. If you type in at the shell prompt mysql. Do you get a prompt like this mysql> If so your login details for your site are localhost root and no password. But you should go and read the docs on how to lock mysql down.