innerjoin

It is necessary to make sure the machine's host name is correct before installing MySQL, as the installation creates a couple of system administration accounts, based on 'localhost' and the name returned by the hostname command. If you install MySQL onto a machine which thinks of itself as 'localhost.localdomain' and set up the proper name later you will need to create new admin accounts and tidy away the old, hopefully unusable, ones.

The two tools to check the hostname are hostname and the humble ping. The latter because it both tests connectivity and does a 'reverse lookup' of the name of the machine it is talking to in the same way as the MySQL does.

Checking the hostname

hostname should give the fully qualified name of the machine, so for example it should return rh.mymachine.org instead of a plain rh.

Checking the reverse lookup

• ping 127.0.0.1

Should give you lines saying something like:

• 64 bytes from localhost (127.0.0.1)....

and not localhost.localdomain (a variation which RedHat includes in the /etc/hosts file). Pinging the fully qualified name

• ping rh.mymachine.org

Should give you lines saying something like:

• 64 bytes from rh.mymachine.org ....

and not a plain and maybe ambiguous rh.