We have decided that RAID1 would be the best fit for our usage scenario for the following reasons:
1). Our overall storage requirements are relatively modest (< 500GB)
2). RAID1 offers the most simplicity in terms of controller overhead and ease of recovery from a failed drive
The only issue that worries us is simultaneous drive failure. In a standard two drive RAID1 setup this would be terminal.
So the question is, are there any hardware raid controllers that allow the mirroring of 3 drives (preferably with a 4th acting as a hot-spare)? The probability of three drives failing simultaneously is sufficiently tiny not to bother us.
As far as I can tell this might be possible in software raid but doesn't seem to be an option if you want to use a hardware controller?
Any advice (or alternative approaches) welcome!
Best Answer
RAID 1 doesn't allow for three-disks mirrors; I know of no hardware RAID controller that can do that.
With some controllers, you can have a hot spare, which is a standby disk that's immediately used to rebuild the volume, should a drive failure happen.