Re: raidframe performance question

[Paul Goyette <paul%whooppee.com@localhost>]

On Thu, 5 May 2011, Michael L. Hitch wrote:

> > 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.

dkctl seems to indicate that the write-back cache is _enabled_

        {295} dkctl /dev/wd5d getcache
        /dev/wd5d: read cache enabled
> > >         /dev/wd5d: write-back cache enabled
        /dev/wd5d: read cache enable is not changeable
        /dev/wd5d: write cache enable is changeable
        /dev/wd5d: cache parameters are not savable
        {296} dkctl /dev/wd4d getcache
        /dev/wd4d: read cache enabled
> > >         /dev/wd4d: write-back cache enabled
        /dev/wd4d: read cache enable is not changeable
        /dev/wd4d: write cache enable is changeable
        /dev/wd4d: cache parameters are not savable
        {297}


> --
> Michael L. Hitch                        mhitch%montana.edu@localhost
> Computer Consultant
> Information Technology Center
> Montana State University        Bozeman, MT     USA
>
> !DSPAM:4dc382652436890921115!

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