Operating system on RAID - good idea or bad?
 

Putting the OS on a RAID 1 with the idea that if one drive dies, the other can take over without human intervention. Is this a good idea?

The reason I ask is that I just installed OpenSuse on a machine with this setup. Somehow, the RAID failed completely. Maybe a driver issue, I'm not sure. It's a brand new 3ware card. All i know is that during a 3.5TB mirror of another server, the OS portition of the RAID died & now the machine doesn't boot at all.

This leaves me wondering if the OS on a RAID is a good idea at all. What measures do people employ to ensure uptime re: OS drive, if the OS on the RAID is a bad idea?

We run the OS on raid arrays where I work. We use raid 5, and are using IBM 5i and 7i serveraid adapters. Expensive, but have paid off for us. We have been in the situation where a drive failed, and to be honest, if it wasn't for seeing the amber light on the drive, we wouldn't have noticed. We use hot-swap drives, so it's just a matter of pulling the defunct drive and replacing it.

One of the nice things about the better raid cards is that the OS is not aware of raid at all, it sees the drive array as a single huge drive (or drives, depending on how you configure it). Let the hardware do what it does best, and the OS do what it does best.

I don't know what card the 3ware is you are talking about, but you might consider looking into a higher raid level. If it doesn't support it, get a better card. It'll pay off in the long run.

To answer your question, it's a new 3ware 9560. I don't think they get much higher end than that. It's possible there are other factors at play here - this is a rental machine... I don't know its history.

Sounds like it's not such a bad idea - just having a bad experience now & am wondering if installing an OS on a RADI is typical or not.

Just googled for that card, and looks, at least on the surface, that it's a good card. the raid level 1 is a little scary for me, but probably mostly because I use 5 or 5e almost exclusively.

With that server being a rental, I'm not sure that I'd trust it 100% either. I know this isn't helpfull, but..

My experience with what you are trying to do is with all new IBM equipment, running at raid 5, all hot-swap drives, so my point of view is a little different. I think it's a good idea, but we have a known good platform for it. That makes a very big difference.

One thing that I have learned over the years is that you have to have a balance in the hardware you are using, and the OS has to match it. A fantastic raid card and iffy drives or iffy motherboard, or iffy power supply can cause nightmares. In you situation, I'd look at the hardware closely.

It can definately be done.

Yes. RAID on the OS partitions is a good idea. It's standard practice.

I'm not sure why you're mirrored drive isn't booting, unless you forgot to copy the /boot partition or something like that.

Shilo