The firmware upgrades did not resolve the problem with disk performance, even though we had a good couple of days. Sun’s final analysis led them to the conclusion that the disk array on which mailboxes reside has simply reached a saturation level in terms of I/O rate. This will mean that we will have to get a faster disk array.

For now, we’ve settled on moving faculty and staff to another disk built into the system. THis has spread the load over two disks, and seems to have alleviate most of the problems. The disk array, which has student mailboxes on it, is still quite busy, and so Webmail may be slow at periods of high loads, typically mid to late afternoon.