Mac OS X Server 10.6 – Apple’s software mirrored RAID worth it

mac-osxmirrorosx-snow-leopardraidsoftware-raid

I am installing an Intel Xserve (Quad core Xeon) with Snow Leopard Server (10.6) on two 80Gb 7200rpm SATA HDs.

I created a mirrored RAID set using Disk Utility with those two drives, all went fine.

I was then asking myself if this is really a good idea. I know that an hardware RAID system would be better, but what about this software RAID?

Have you any feedback on this? Will it work fine if one HD breaks down? Does this affect performance?

[UPDATE]

In short: Hardware RAID is better than software RAID which is better than none.

Thank you all for the answers, they were very helpful.

Especially Gordon's script to monitor failures. As Apple's software RAID is pretty silent about a drive failure.

Best Answer

My personal preference is always for hardware RAID but would use software over none. I am also aware there are some who have the opposing view. Yes, it will continue to function if one of the drives fail. That is the main reason to use RAID. The "R" stands for redundant.

Software RAID must impact performance because the CPU is having to do more. However, in reality if that difference becomes noticeable you're pushing the server far too hard, which will result in more problems than the loss of a few CPU cycles. e.g. Heat will become a serious concern.

One question I would ask is why such tiny drives? For very little more you can get much larger drives. If nothing else, 80GB drives are becoming quite hard to source, which may be an issue from the future maintenance point of view.