-- Sent from my mobile device On 13.03.2013, at 18:38, "Josh Durgin" <josh.durgin@xxxxxxxxxxx> wrote: > On 03/12/2013 12:46 AM, Wolfgang Hennerbichler wrote: >> >> >> On 03/11/2013 11:56 PM, Josh Durgin wrote: >> >>>> dd if=/dev/zero of=/bigfile bs=2M & >>>> >>>> Serial console gets jerky, VM gets unresponsive. It doesn't crash, but >>>> it's not 'healthy' either. CPU load isn't very high, it's in the waiting >>>> state a lot: >>> >>> Does this only happen with rbd_cache turned on? If so, it may be the >>> same cause as http://tracker.ceph.com/issues/3737. >> >> Indeed it does only happen with rbd_cache turned on. Without the cache >> the jerking doesn't happen, but it's slower by a factor of three (well - >> we knew this before, right): >> >> (without rbd-cache): >> dd if=/dev/zero of=/bigfile bs=2M count=100 >> 209715200 bytes (210 MB) copied, 9.32188 s, 22.5 MB/s >> >> (with rbd-cache): >> dd if=/dev/zero of=/bigfile bs=2M count=100 >> 209715200 bytes (210 MB) copied, 3.12769 s, 67.1 MB/s >> >> And yes, we've also seen lost packets on the network on a busy machine >> with rbd_cache, so this is totally the issue in the bugtracker. > > Anyone seeing this problem, could you try the wip-rbd-cache-aio branch? Checked it out but ran Out of Time, so i won't be able to Report back until monday. > Thanks, > Josh Thank you, Wolfgang _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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