Good benchmarking tool?

[Matias Gut]

I had some troubles with a PowerEdge 2850 so I decided to take it out of 
production, in order to analize the problem.
For the first test I did I find that access time to hard disks is quite 
slow.

Anybody knows a good tool to benchmark disk access? I'm running Fedora 
Core 5 on that server. I think I'll update to a newer version, may be FC 
9 or Centos, but I'd like to do some benchmarks before updating to see 
if the problem is related to operational system or hardware based.

Thanks in advance,
Matías