Quick questions on RAID5

Aono · 18 Oct 2009 at 12:58

I'm going to be using a 3x1TB RIAD5 setup for storage. Never used raid before so I got some quick Qs:

1. If the motherboard dies does this risk your data?
2. How easy is it to move a RAID5 setup from one pc to another? Same process as a single drive?
3. What's the biggest risk to a RAID5 setup apart from simultaneous drive failure?

Thanks.

AbsenceJam · 18 Oct 2009 at 15:13

If you move the array it has to be to the same series of controller and typically it will work.
RAID5 arrays can run into corruption issues and suffer problems caused by power loss, crashes etc.

Xelene · 19 Oct 2009 at 12:11

I wouldn't use motherboard Raid 5 tbh.

PistolPete · 19 Oct 2009 at 12:46

2. How easy is it to move a RAID5 setup from one pc to another? Same process as a single drive?

If you move the array to a board with a like RAID controller, then it should in theory just carry on running - most on-board RAID write the config data to the disks so the config goes with them. I'm not sure how well the new controller will handle the disks being the wrong way around, to I mark all my disks and plug into the same numbered port. I've moved arrays around from board to board like this without problems.

3. What's the biggest risk to a RAID5 setup apart from simultaneous drive failure?

So long as you understand the only benefit of of RAID5 is the ability to run with 1 disk failed you shold be fine. It's not a substitute for backing up data so do no rely on it. The other problem with onboard RAID5 is the write speeds can be horrible.

I think that people to tell you to stay away from on-board RAID have a point to a certain extent, but it's a handy tool if used the right way.
I run 6TB RAID5 from an onboard controller - but I backup all the critical stuff to 1 onsite and 1 offsite location, and the not so critical stuff I'm happy to lose should the worst happen. Ditto with the 4 disk RAID0 running my gaming machine. I store no critical data on it so should the array fail I simply re-image the machine.

Aono · 19 Oct 2009 at 17:44

Thanks for the info.

AbsenceJam · 19 Oct 2009 at 19:02

If the data you're planning on storing doesn't change to much then look into disparity or flexraid, they're parity solutions but aren't live so you need to update the parity after changes if you want redundancy.