[ale] Need an off the shelf linux recommendation
freemyer-ml at NorcrossGroup.com
Wed Feb 4 17:21:24 EST 2004
On Wed, 2004-02-04 at 16:45, Dow Hurst wrote:
> I thought 0+1 was mirroring two drives? Is it two mirrors
> of two drives?
0 = striping (ie. no fault tolerance, done for performance reasons.)
1 = mirroring (fault tolerant)
I have trouble remembering which is 0+1 and 1+0, but each takes 4 drives
minimum. The max. drives in either is hardware/software specific.
I think 0+1 is 2 stripsets mirrored together.
1+0 is 2 mirrorsets striped together.
The best way is mirrorsets striped together. It can survive more 2
drive failures than if you set it up the other way around.
A 4-disk RAID 1+0 setup will survive 2/3 of all 2 disk failures.
A 4-disk RAID 0+1 setup will only survive 1/3 of all 2 disk failures.
A 10-disk RAID 1+0 setup will survive 8/9 of all 2 disk failures.
A 10-disk RAID 0+1 setup will only survive 4/9 of all 2 disk failures.
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