Home RAID question

[Corey Edwards]

On Thu, 2006-05-11 at 11:07 -0600, Michael L Torrie wrote:
> Most consumer raid cards are really just software raid done in the
> driver anyway.  I've seen benchmarks that showed Linux' software RAID
> works very well (RAID 0,1,5).  I have been quite happy with software
> RAID for my home machine.  I know that Andrew McNabb is using about a
> terabyte or more done with software RAID.

As Josh pointed out, the most important benefit of hardware raid is
battery-backed cache. I doubt you'll get that on a $20 card anyway, so I
don't see the point either. I use software RAID1 on a lot of machines
and it works great. Saved our bacon in a number of cases.

> As has been mentioned in the past, RAID 10 (or is it 0+1 -- I can't
> remember) can give you many of the benefits of RAID 5 but is simpler in
> some ways.  Basically the desired configuration is a striping across 2
> or more RAID-1 (mirrored) sets.  

IMHO RAID10 surpasses RAID5 in all ways, except for the percentage of
usable disk. RAID10 gives you exactly 50%, where RAID5 is higher. The
tradeoff is just that the more redundant data, the less chance of a
total meltdown. And the more disks in a RAID the higher the chance of 2
going out simultaneously, which for RAID5 means game over.

Also remember that RAID != backups. RAID1 pairs do die. I've seen it
happen, and without a recovery plan the results can be a nightmare.

Corey

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 191 bytes
Desc: This is a digitally signed message part
Url : http://plug.org/pipermail/plug/attachments/20060511/d40b0db2/attachment.pgp