Re: AMD64 System Becomes Unresponsive During Software RAID Synchronization
On Mon, Oct 03, 2005 at 09:51:22AM -0400, Lennart Sorensen wrote:
> 2.6 kernels currently default to using up to 200M/s for resync. This
> causes seriously painful disk access while this is taking place.
>
> I personally always drop it to 10 or 15M/sec so that I can still work on
> the system while it syncs the raid. This is done like this:
>
> echo 10000 > /proc/sys/dev/raid/speed_limit_max
>
> System becomes responsive again and the resync only takes about twice as
> long or so. It certainly takes longer.
Have you tried using an other I/O scheduler (like cfq or deadline) on
the affected drives? According to my experiences, the default
anticipatory scheduler is very bad interactivity-wise when there is
heavy disk activity. On the other hand, anticipatory gives much better
throughput than cfq, so you have to decide what do you need.
Gabor
--
---------------------------------------------------------
MTA SZTAKI Computer and Automation Research Institute
Hungarian Academy of Sciences
---------------------------------------------------------
Reply to: