Re: slow performance on disk/network i/o full speed afterdrop_caches

From: Wu Fengguang
Date: Wed Aug 24 2011 - 05:33:48 EST


On Wed, Aug 24, 2011 at 05:01:03PM +0800, Stefan Priebe - Profihost AG wrote:
>
> >> sync&& echo 3>/proc/sys/vm/drop_caches&& sleep 2&& echo 0
> >>> /proc/sys/vm/drop_caches
>
> Another way to get it working again is to stop some processes. Could be
> mysql or apache or php fcgi doesn't matter. Just free some memory.
> Although there are already 5GB free.

Is it a NUMA machine and _every_ node has enough free pages?

grep . /sys/devices/system/node/node*/vmstat

Thanks,
Fengguang

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