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Home -> Community -> Usenet -> c.d.o.server -> Veritas's implementation/interpretation of RAID 0+1 and RAID 10
My understanding w/ RAID 0+1 and RAID 10 was always the following
RAID 0+1
First stripe, then mirror
If you lose one drive on the mirror, you lost the entire mirror
If you lose two drives on different mirrors (plexes) you lose all data
RAID 10
First mirror, then stripe
You can lose tons of disks, and still be OK, as long as no 2 failed
drives are mirrors of each other (and this wouldn't only happen if two
mirrors fail concurently if you have some spares)
cons? (more complex? less flexibility?)
But here's what veritas says:
http://seer.support.veritas.com/docs/231471.htm
(the naming seems completely reversed! Am I stupid, or is Veritas?) Mirror-stripe they call RAID 10, but desc seems to be for RAID 0+1 Stripe-mirror they call RAID 0+1, but desc seems to be for RAID 10
Advantages/Distinctions
If a disk fails in a mirror- stripe layout, the entire plex is
detached, thereby losing redundancy on the entire volume. When the
disk is replaced, the entire plex must be brought up to date.
Recovering the entire plex can take a substantial amount of time. If a
disk fails in a stripe-mirror layout, only the failing subdisk must be
detached, and only that portion of the volume loses redundancy. When
the disk is replaced, only a portion of the volume needs to be
recovered.
Compared to mirroring plus stripping, stripping plus mirroring offers
a volume more tolerant to disk failure. If a disk failure occurs, the
recovery time is shorter for stripping plus mirroring.
The way it's supposed to be:
RAID 0+1
http://www.acnc.com/04_01_0p1.html
RAID 10
http://www.acnc.com/04_01_10.html
.......
We use Oracle 8.1.7.3 on Solaris 2.7 boxes
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Received on Tue Aug 20 2002 - 13:03:04 CDT