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Re: raidframe performance question

On Thu, 5 May 2011, Paul Goyette wrote:

The next step was to initialize the raidset parity, so I used raidctl -i

That was almost 10 hours ago, and so far it has done only 26% of the job! It appears that the writes are taking ~forever to complete! systat(1) shows that wd5 (I'm assuming that's the "parity" drive being written) has twice the transfer-ops and twice the bytes-transferred, but the drive is 100% busy!

Disks: seeks xfers bytes %busy
  wd5         165 5286K   100
  wd4          83 2643K   2.2

Does anyone have a clue why the drive might be so busy?  Is this normal?
At this rate it will take another day to initialize a 465GB mirror! With a SATA-II transfer speed of 3Gbytes/sec (300MBytes/sec) it really should be a little bit faster. :)

I wouldn't consider it normal. I would suspect that the write cache on the drive is off, and writes are very slow. You could check that with dkctl, and enable the write cache for the parity initialization if the write cache is off.

Michael L. Hitch              
Computer Consultant
Information Technology Center
Montana State University        Bozeman, MT     USA

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