Re: raidframe performance question

["Michael L. Hitch" <mhitch%lightning.msu.montana.edu@localhost>]

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
>   cd0
>   wd2
>  nfs0
>  nfs1
>   wd0
>   wd5         165 5286K   100
>   wd4          83 2643K   2.2
> raid1
>
> 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                        mhitch%montana.edu@localhost
Computer Consultant
Information Technology Center
Montana State University        Bozeman, MT     USA