I just tested from the v10.2.3 git tag on my local machine and averaged 2912.54 4K writes / second with "rbd_cache_writethrough_until_flush = false" and averaged 3035.09 4K writes / second with "rbd_cache_writethrough_until_flush = true" (queue depth of 1 in both cases). I used new images between each run to ensure the there wasn't any warm data. What is the IOPS delta percentage between your two cases? What is your QEMU cache setting for the rbd drive? On Fri, Oct 21, 2016 at 9:56 AM, Pavan Rallabhandi <PRallabhandi@xxxxxxxxxxxxxxx> wrote: > From my VMs that have cinder provisioned volumes, I tried dd / fio (like below) to find the IOPS to be less, even a sync before the runs didn’t help. Same runs by setting the option to false yield better results. > > Both the clients and the cluster are running 10.2.3, perhaps the only difference is that the clients are on Trusty and the cluster is Xenial. > > dd if=/dev/zero of=/dev/vdd bs=4K count=1000 oflag=direct > > fio -name iops -rw=write -bs=4k -direct=1 -runtime=60 -iodepth 1 -filename /dev/vde -ioengine=libaio > > Thanks, > -Pavan. > > On 10/21/16, 6:15 PM, "Jason Dillaman" <jdillama@xxxxxxxxxx> wrote: > > It's in the build and has tests to verify that it is properly being > triggered [1]. > > $ git tag --contains 5498377205523052476ed81aebb2c2e6973f67ef > v10.2.3 > > What are your tests that say otherwise? > > [1] https://github.com/ceph/ceph/pull/10797/commits/5498377205523052476ed81aebb2c2e6973f67ef > > On Fri, Oct 21, 2016 at 7:42 AM, Pavan Rallabhandi > <PRallabhandi@xxxxxxxxxxxxxxx> wrote: > > I see the fix for write back cache not getting turned on after flush has made into Jewel 10.2.3 ( http://tracker.ceph.com/issues/17080 ) but our testing says otherwise. > > > > The cache is still behaving as if its writethrough, though the setting is set to true. Wanted to check if it’s still broken in Jewel 10.2.3 or am I missing anything here? > > > > Thanks, > > -Pavan. > > > > _______________________________________________ > > ceph-users mailing list > > ceph-users@xxxxxxxxxxxxxx > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > -- > Jason > > -- Jason _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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