linux server slow.

[unix syzadmin]

Hi,

The users in my team are running tests for weblogic on linux (RHEL AS4).  We
generally run test for weblogic on different operating system and certify
it.
They have complained that the linux server is slow.  A test that usually
would take 30 mins is taking about 5 hours.
They have not faced this kind of slowness with any other server (solaris,
aix & hp-unix), even the earlier servers that were running linux.

I am new to troubleshooting performance problems.  Please suggest.

Thanks & Regards,
-GnanaShekar-