On Mon 10 Jul, 2000, Frank Smith fsmith@hoovers.com wrote:
Wouldn't it be at least slightly risky to pull all your spares plus one of your data drives for the duration of a rebuild?
Yes. Therefore it's not really recommended.
You can of course replace all the spares as soon as the rebuild is suitably underway - which should allow for further rebuilds on other RAID groups if you have a multi-disk failure of that type.
If you have a real disk failure in the RAID group you just artificially pulled a disk from, then you start writing the apology emails and calling the ops to bring the tapes back on-site..
Overall, this creates additional work, and as laziness is a virtue, I, personally, wouldn't go pulling disks to neaten up my RAID groups.
(similar case: because the filer uses RAID4 not RAID5, and is a pretty smart cookie, you can achieve Great Things(tm) by not having a spare around and pulling the parity disk in each RAID group in a volume... the risk/benefit analysis is an exercise for the reader)
Frank -- End of excerpt from Frank Smith