From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: Re: production ready? Date: Tue, 30 Oct 2012 21:32:01 +0100 Message-ID: <50903941.90805@profihost.ag> References: <508EE540.5060303@inktank.com> <508FD83F.9020308@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.profihost.ag ([85.158.179.208]:37723 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934369Ab2J3UcE (ORCPT ); Tue, 30 Oct 2012 16:32:04 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Gregory Farnum Cc: Dan Mick , ceph-devel@vger.kernel.org Am 30.10.2012 14:45, schrieb Gregory Farnum: >> But there's still the problem of slow random write IOP/s. At least i= haven't >> seen any good benchmarks. > > It's not magic =97 I haven't done extensive testing but I believe peo= ple > see aggregate IOPs of about what you can calculate: > (number of storage disks * IOPS per disks) / (replication level) > The journaling bumps that up a little bit for bursts, of course; > similarly if you're doing it on a brand new RBD image it can be a bit > slower since you need to create all the objects as well as write data > to them. You need to architect your storage system to match your > requirements. If you want to run write-heavy databases on RBD, there > are people doing that. They're using SSDs and are very pleased with > its performance. *shrug* My last test was with 0.49 so i can't talk about 0.52 but as far as i=20 know nothing has changed in this case. I had 6 Dedicated servers running each with 4x Intel 520series SSDs=20 running 4 OSDs (one OSD per disk). I had the journal running in tmpfs=20 1GB size to be sure it isn't the bottleneck. Replication was set to 2. Each SSD is capable of doing 30.000 IOP/s random 4k. But with RBD i wasn't able to get more than 20.000 IOP/s but overall i = had: 6 ded. servers * 4 SSDS =3D> 24 OSDs/SSDs * 30.000 IOP/s / Replication = 2=20 =3D> 360.000 iop/s theoretical overall performance But i didn't get more than 20.000 while using 3.6Ghz Xeon CPUs and Dual= =20 10GBE. Greets, Stefan -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html