Hi
Performance analysis/tuning is always a bit of a circular process - you will never escape the bottleneck of your slowest component.
The thing to do is to follow an ordered, disciplined sequence. Where is your bottleneck now?
Start with the CPU. If the system performance is not bound by the CPU, is it constrained by memory? If not memory, what about disk I/O? Failing that, move on to the network interfaces. Finally, look at the application(s). This is the general rule.
There are various methods, but I have seen many people reporting great success using NMON - available as a free download from IBM. It provides you with a point-in-time overview of the system, whilst at the same time generating historical data that can be viewed as graphs in Excel.
Personally, I favour simple tools like "ps aux", "vmstat", "iostat", "sar", "filemon", and "fileplace", because these are usually enough to reveal any configuration howlers that would be contributing to any slowness that I might be experiencing. I'd turn to the more complex tools like NMON if I failed to reveal anything using the simpler methods...
HTH
Kind Regards,
Matthew Bourne
"Find a job you love and never do a day's work in your life.