Am 11.02.2015 um 08:44 schrieb Alexandre DERUMIER: >>> same fio, same qemu, same vm, same host, same ceph dumpling storage, >>> different librados / librbd: 16k iop/s for random 4k writes >>> >>> What's wrong with librbd / librados2 since firefly? > > Maybe could we bissect this ? > > Maybe testing intermediate librbd releases between dumpling and firefly, > > http://gitbuilder.ceph.com/ceph-deb-wheezy-x86_64-basic/ref/ Yes may be. Sadly i've currently another problem on my newest cluster having strange kworker workload - i've never noticed before on any ceph system. All writes are hanging - while using the same kernel as everywhere. Stefan > > could we give us an hint. > > > ----- Mail original ----- > De: "Stefan Priebe" <s.priebe@xxxxxxxxxxxx> > À: "ceph-devel" <ceph-devel@xxxxxxxxxxxxxxx> > Envoyé: Mardi 10 Février 2015 19:55:26 > Objet: speed decrease since firefly,giant,hammer the 2nd try > > Hello, > > last year in june i already reported this but there was no real result. > (http://lists.ceph.com/pipermail/ceph-users-ceph.com/2014-July/041070.html) > > I then had the hope that this will be fixed itself when hammer is > released. Now i tried hammer an the results are bad as before. > > Since firefly librbd1 / librados2 are 20% slower for 4k random iop/s > than dumpling - this is also the reason why i still stick to dumpling. > > I've now modified my test again to be a bit more clear. > > Ceph cluster itself completely dumpling. > > librbd1 / librados from dumpling (fio inside qemu): 23k iop/s for random > 4k writes > > - stopped qemu > - cp -ra firefly_0.80.8/usr/lib/librados.so.2.0.0 /usr/lib/ > - cp -ra firefly_0.80.8/usr/lib/librbd.so.1.0.0 /usr/lib/ > - start qemu > > same fio, same qemu, same vm, same host, same ceph dumpling storage, > different librados / librbd: 16k iop/s for random 4k writes > > What's wrong with librbd / librados2 since firefly? > > Greets, > Stefan > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
