On 22-Jan-99 [EMAIL PROTECTED] wrote:
> 1) RAID 0+1 is creating two stripes, and mirroring one onto another.
> RAID 1+0 is mirroring each drive to another, and striping across
> the resulting volumes.
>
> They aren't the same thing. Really. They aren't.
I'm reliably told 0+1 and 1+0 _are_ the same thing. Either way, you create
stipes across a set of disks, and then mirror the set of disks to another set
of disks. You can lose all the disks on one side of the mirror and still be
operational.
Raid 0 is striping, raid 1 is mirroring. There is logically only one way to
combine the two correctly, ie you mirror your stripes. This is variably termed
0+1 or 1+0.
>
> with 0+1, the second drive you lose results in the loss of the data.
Only if it's on the opposite side of the mirror from the first lost disk and on
the same stripe.
> with 1+0, you can lose one drive from each mirrored pair, and still
> maintain data integrity. It's the no-compromise approach to RAID
> sets.
I think you mean raid 10? http://www.whatis.com/raid.htm says:-
"RAID-10. This type offers an array of stripes in which each stripe is a
RAID-1 array of drives. This offers higher performance than RAID-1 but at
much higher cost."
> RAID 5 has slow writes which make it unadvisable for data that undergoes
> updates on a minute to minute basis.
Agreed. Can't see why anyone would want raid 5.
> Personally, I'm not into server controller based RAID. I'd rather have
> the RAID look like a drive on the SCSI bus...
Yup, hardware raid is indubitably better.
> --
> John White
> [EMAIL PROTECTED]
> PGP Public Key: http://www.triceratops.com/john/public-key.pgp
Cheers!
Brian
