Re: Software RAID (non-preempt) server blocking question. (2.6.20.4)

From: Neil Brown
Date: Fri Mar 30 2007 - 00:39:15 EST


On Thursday March 29, jpiszcz@xxxxxxxxxxxxxxx wrote:
>
> >
> > Did you look at "cat /proc/mdstat" ?? What sort of speed was the check
> > running at?
> Around 44MB/s.
>
> I do use the following optimization, perhaps a bad idea if I want other
> processes to 'stay alive'?
>
> echo "Setting minimum resync speed to 200MB/s..."
> echo "This improves the resync speed from 2.1MB/s to 44MB/s"
> echo 200000 > /sys/block/md0/md/sync_speed_min
> echo 200000 > /sys/block/md1/md/sync_speed_min
> echo 200000 > /sys/block/md2/md/sync_speed_min
> echo 200000 > /sys/block/md3/md/sync_speed_min
> echo 200000 > /sys/block/md4/md/sync_speed_min
>

Yes, well....

You told it to use up to 200MB/s and the drives are only delivering
44MB/s, so they will be taking nearly all of the available bandwidth.
You shouldn't be too surprised if other things suffer.

NeilBrown
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