On Friday 24 March 2006 8:17 am, Per Jessen wrote:
All,
probably a little OT here, but I _am_ using SUSE Linux :-)
I'm trying to work out the optimal (or near-optimal at least) RAID configuration of a 24-disk array. The array comes with two redundant RAID controllers each with six SCSI channels. These controllers allow all kinds of RAID0/1/5 configurations, but no RAID6.
I want the array to be able to survive a two disk failure, so RAID6 would be the obvious choice, but ...
Depends. Is the data read or write intensive? What performance parameters are you trying to achieve? What budget are you trying to meet? RAID5/6 is slow on writes. RAID10 (RAID0 + RAID 1) with hot spares would be my idea of surviving multiple drive failures at any time and maintaining decent performance for reads and writes.
So I'm sort of looking at choosing between -
- using plain software RAID6 and ignoring the hardware RAID facilities of the array. - using the hardware controllers to build a combination of RAID0/1/5 that'll give me the two drive failure survivability.
Will these controllers be able to talk to each other in a redundant fashion? At the hardware/firmware/driver level?
I've had a look around the web, but googling for "two drive failure RAID" almost always leads to someone talking about RAID6 ...
So, opinions/suggestions?
Give us more info about the specific hardware and the 'application' you are trying to support. I look to eliminate complexity from a system like this. What is the easiest way to monitor, replace and rebuild the hardware/drives and data you are trying to protect? Redundant controllers are nice but if you can't hot-swap a failed one in a running machine can the 'application' afford the downtime to do a replace and rebuild?
/Per Jessen, Zürich
Stan