From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: speed decrease since firefly,giant,hammer the 2nd try Date: Tue, 10 Feb 2015 19:55:26 +0100 Message-ID: <54DA541E.9000608@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ph.de-nserver.de ([85.158.179.214]:32097 "EHLO mail-ph.de-nserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753297AbbBJSz0 (ORCPT ); Tue, 10 Feb 2015 13:55:26 -0500 Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "ceph-devel@vger.kernel.org" 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