Should I RAID my SSDs?

I have a couple of SATA hard disks RAIDed for safety in my machine, because I'm worried about the drive having some sort of mechanical failure and losing my data. I'm considering switching to an SSD next year when the prices have come done a bit.

Is it worth using a RAID with SSDs? It seems like the major cause of mehanical failure will have been eliminated by using the SSD, so you're basically trading "Chance of SSD failure" for "chance of cheapo motherboard raid controller failure". I'm not sure if that's worth it.

Opinions?


If you don't mind the cost, then there's nothing stopping you from RAIDing SSDs.

Always go with software RAID if you're not running a server! Software RAID is transferable between machines, and hardware RAID often isn't.

Personally, I wouldn't bother with RAID on the current generation of SSDs. Just get the one, and ensure you have sufficient backups that you don't feel concerned about loss of a drive. With the current price and size of SSDs it will be cheap and easy to back up, and then when they get cheaper and larger in the future (as they invariably will) I'd buy more :)

I'd also suggest looking at the MTBF of SSDs and hard disks, and calculating the chances of a failure (and the types of failure -- they may not be as catastrophic with SSDs, as a single sector breaking may not be a sign that the whole drive is dying as it can be with HDDs) and work out if the SSD has a higher or lower chance of failing than a set of RAIDed hard disks...

Edit : The official server fault blog says that this very site is going with RAID-ed SSDs now : http://blog.serverfault.com/post/our-storage-decision/


If you use software raid you remove your "chance of cheapo motherboard raid controller failure". With today's processor speeds, the CPU time required to do the parity calculations is tiny (and you are likely doing this already in the CPU with most half-baked consumer raid chips). When doing some of my own benchmarks I have actually seen software RAID outperform enterprise RAID cards when in write-through mode (I assume your motherboard does not have a battery backed cache to allow you to operate in write-back mode).

So, unless you have something against software raid, I think you lose very little by going with software raid and gain the increased reliability.


SSDs can and do fail. I'd say yes RAID them just to be safe.