Thread: RAID5 suxx
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Old 10-06-2012, 22:51   #1
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RAID5 suxx

So, I bought three 3TB drives and made a RAID5 with them, despite numerous advices against it (there is even a society called BAARF - Battle Against Any RAID Four/Five).

But, of course, I just had to see it for myself...

With the "fake" onboard RAID controller (Intel ICH10R), I did not expect any stellar results. But the reality was even worse than I expected.

First of all, it took two days to initialize the RAID. You can use the arrays before and during initialization, but the performance would be really abysmal. So what did I get after the long wait was over?

Sequential read speed: down 27% compared to a standalone disk.
Sequential write speed: down 44%.
512K block read speed: down 32%.
512K block write speed: down 88%. Ouch.
4K block read speed: up 4%. Probably just a statistical deviation.
4K block write speed: down 12%.
4K block read with queue depth 32: up 125%.
4K block write with queue depth 32: down 8%.

I think I should go buy one more drive and make a RAID10.
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