[NTLUG:Discuss] Raid drive failed, do I need to match it?

[Pat Regan]

Neil Aggarwal wrote:
> Will it be a problem to use a different brand and drive speed
> for the replacement drive for my array?

There is an advantage to running different model/brand drives in a
RAID...  They are less likely to fail at the same time :).  There
shouldn't be any problem running two drives of different speeds.  Your
read speeds will probably increase to some extent, I would imagine.

I am not sure why everyone wants identical drives with today's RAID
technology.  In the early days of RAID all drives were kept basically in
sync and the whole array ran at the speed of the slowest drive.  Today,
most implementations can take advantage of the redundant data to provide
a boost to read performance.  This does a good job of keeping the heads
out of sync :p.

There is one gotcha to watch out for, however.  Not all 36 gig drives
are exactly the same size.  As a real world example, I had a failed 160
GB IDE drive in a mirror fail.  It was a western digital drive and I had
a Maxtor 160 on hand to use in its place.

My 3ware card says the WD drives are 160 GB and the Maxtor is 163 GB.
Fortunately for me, the temporary replacement was larger than the
original.  I would have been SOL had it been the other way around.

Pat