Quote Originally Posted by zeki893
/dev/sdb: Timing buffered disk reads: 492 MB in 3.00 seconds = 163.82 MB/sec
/dev/sdc: Timing buffered disk reads: 304 MB in 3.01 seconds = 101.09 MB/sec
/dev/sdd: Timing buffered disk reads: 264 MB in 3.00 seconds = 87.86 MB/sec
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G'day,
Well I've not used the MD1000's, but I am surprised that there is a 15% difference between the two. But at least they are close. Also I am surprised to see such a drop in performance between Raid5 and Raid6. Logic would say that the added spindles would have given the 30x1TB an edge, although perhaps there is an issue with the split between the 2xMD1000's.
Anyway, the performance here does seem low, I would have expected better.
A post here implies speeds of 600MB/s are possible once the Read Ahead of the kernel is tweaked.
Now, before I continue I wish to say that I HAVE NOT tried this, and I am NOT a storage guru!
But in the Console Tools there is a Read Ahead option, which I believe to be the same as the above. So setting it to 8192 or 16384 may improve things?
But I would get confirmation from an expert before you put it into production....

RE The naming, I can't help here, not sure how DSS decides or how you can confirm it.
But I think it's pretty clear at least that c/d are the MD1000's. Since the sdb has been consistent.

Rgds Ben.