Re: RAID support different size hard drives

If only one fails and you replace it before a second one fails, yes, you are
fine. If you are on vacation in Tahiti and one fails, then another fails
three days later when you don't know about the first one that failed, the
data is toast.

The whole point of a "hot" spare is that it is an automatic replacement.

Gregg Hill


"gr" <guybo@xxxxxxxxxxxxxx> wrote in message
news:1168524693.028646.105800@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
In regards to hotspare drives. Is it essential? I don't have a hot
spare installed as I didn't have any extra room in my drive bay.
BUT... I do have an identical extra drive sitting in the safe in case
any of the drives fail. Will my data integrity be ok if one fails with
this method?

TIA
Guy


SuperGumby [SBS MVP] wrote:
a key point has been mentioned, software or hardware RAID? (and if you're
talking about your SBS it better be hardware)

Susan has dealt with software RAID so I'll throw some comments about
hardware.

The drives should not only be the same size but the same geometry
(sectors,
heads, cylinders) which is why the general conception is 'same make, same
model'. They should also be same interface (ie/eg. all SCSI320).

I like Gregg's comment about the four drives. Yes, every array should
have a
hotspare. As you need 3 minimum for RAID5, plus the hotspare, this may be
why you've been told 4 drives. Another consideration is performance.

read/write performance of RAID5 improves as the number of drives
increases,
up to the point where the aggregated sustained throughput of the drives
exceeds the throughput of the channel or controller.

an interesting thought relates to this page
http://www.acnc.com/04_01_05.html
Compare the 'Recommended Application' list to SBS facilities.

<suli222@xxxxxxxxx> wrote in message
news:1168453993.833212.197280@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I am not very familiar with RAID 5 at all. My questions is can RAID
supporting configuring different size hard drives. For instance if I
had a 250, 200, 120, and 80 GB hard drives, can RAID support all these
HDs in one PC. My second questions it seems like RAID 5 works best
with 4 hard drives, is this true.




.

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