On Apr 12, 2011, at 12:31 AM, John R Pierce wrote:
On 04/12/11 12:23 AM, Matthew Feinberg wrote:
Hello All
I have a brand spanking new 40TB Hardware Raid6 array
never mind file systems... is that one raid set? do you have any idea how LONG rebuilding that is going to take when there are any drive hiccups? or how painfully slow writes will be until its rebuilt? is that something like 22 x 2TB or 16 x 3TB? I'll bet a raid rebuild takes nearly a WEEK, maybe even longer..
I am very strongly NOT in favor of raid6, even for nearline bulk backup storage. I would sacrifice the space and format that as raid10, and have at LEAST a couple hot spares too.
+1 for the 1+0 and a few hot spares.
Raid 6 + spare ran great but rebuilds took 2 days. The likely hood of 2+ failed drives is less then 1 failed drive but I actually had 2 failed drives so RAID6 + spare saved me.
Hence why I switched to RAID 1+0 + spares.
A tuned XFS fs will work great.
I run my large RAID XFS fs with logbufs=8, and no(atime.dirtime).
I also run iozone for testing my tuned options for optimum performance in my env.
- aurf