Where can I look to see what is causing a high load on a cluster server when a Groupwise resource is loaded on that server?

I've done top command and don't see anything that stands out.
What log files could I check?

OES2 SP2a
Groupwise 7

This is a new installation of OES2 SP2a and an ID Transfer was done to migrate the cluster server being upgraded from OES1 SP2 to OES2 SP2a.

thanks,
Lin