Ulrik S. Kofod wrote:
>I have 3 disks that I want to setup in a raid 1, my questions is should I setup the
>3rd disk as a spare-disk or should I mirror all 3 disks all the time?
>
>Will it perform *much* better to only mirror two and have the 3rd as a spare.
>Is it not safer to mirror all 3 drives all the time ?
>
>
>
I really don't understand the question. RAID-1 requires an even number
of disks since disk(s) A simply is a mirror image of disk(s) B. So with
3 disks you could have a 2-drive mirror and designate the 3rd drive as a
hot spare. So if one of your mirrored drives fails, the hot spare takes
over. You could just as easily do a 3-disk RAID-5 array. It would be
substantially faster on reads than a 2-disk mirror. It could be faster
or slower on writes depending on which hardware RAID card you're using
or how fast your processor is if you're doing software RAID.
Cheers,
