I've got a HP DL360 G3 with twin 73GB scsi u320 15k drives on a 64MB smart array 5i in raid 1. The CPUs are twin Xeon 2.8s.
The system has CentOS 5 installed and patched to be fairly current (using yum)

The system runs fine, and under a slight load, it performs fine. But the instant a heavy I/O load hits (like migrating a VMware VM to it) the load average jumps to over 10.00 and the whole system becomes unresponsive (not entirely, but REALLY slow).

Now I know Linux is not really that good at multi tasking under heavy I/O load, but this seems ridiculous. The drive is accessed via /dev/cciss/c0d0p1, so its using the cciss driver, but something has got to be wrong. I updated the firmware on the 5i controller, to no avail.

Anyone have an idea of where to look for settings, etc??

TIA very much!