Re: [libvirt-users] LXC + passthrough mount and host filesystem-cache
On Wed, Mar 26, 2014 at 02:52:58PM -0500, James R. Leu wrote:
Hello,
I'm using libvirt to build/run LXC instances. My LXC instances use
passthrough filesystem mounts. When I try to do large file systems
operations (ex tar or rsync) the file systems cache on the host
spikes and causes the OOM handler to run and kills processes
in the LXC.
So it is specifically targetting processes inside the container
and not the host ?
If you run the same tar/rsync operations outside the container
on the same filesystem, presumably you don't see the OOM killer
behaviour ?
Has anyone else seen this? Is there a way around this?
At this point I'm resorting to running a cron job that dumps
the filesystem cache every 5 minutes. The result is the filesystem
cache on the host never grows too large and OOM never runs against
LXC processes. The obvious down fall is that I'm killing my filesystem
performance by duming the cache.
This is the first I've heard of this problem and it certainly
seems odd/bad. I wonder if there's some cgroup tunables that
are being set badly, or that need to be set ? Or some global
proc/sysfs settings
Regards,
Daniel
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