Ciaran wrote:
Ouchies! Were you getting errors or did you just happen to notice it while pottering about?
Ciarán
Noticed a red light on the drive when I went to insert a new backup tape

I check it every few days so it's not been down long. Had I been a good sysadmin I would have noticed the problem in the event logs.. My bad...
It's worse than that. The array is not rebuilding properly and the disk is reporting errors even though the disk is fine in another array. That means the storage box has a problem and that is not hot-swappable

A common enough problem on these old Compaq ML series servers.
I'll get some spares tomorrow and then get it sorted. In the meantime, if the forum dies you know why...
No worries though as I have a contingency...