We have a RAID-5 array {6 disks} at

[corpanarchy]

We have a RAID-5 array {6 disks} attached to a seperate server with an Adaptec 2210 card. Recently we had a disk fail, which has since been replaced. We've been having all sorts of problems:

Novell reporting that Domain Validation Had to Decrease Speed {changed the speed type in the Adaptec config, to no avail.}

Intermittently detected disks, rebuilding claim failed, on reboot of array claims to be rebuilding again at same percentage mark.

All 6 disks save the third being detected as "missing component"

I suspect it has something to do with the speed of the connection but I've attempted all of the settings in the Adaptec BIOS, to no avail. All drives are IBM/Hitachi.

What I've done:

Tried rebuilding the array
Tried formatting the failed disks
Changed the speed in the BUS options of the Adaptec BIOS
Removed all disks and replaced one by one

I'm completely at a loss. The Adaptec site says to change the speed of the card and check for failed devices. Done both and removed the failed disk.

Any ideas?