From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: Re: mon disk access pattern Date: Fri, 15 Jun 2012 22:31:27 +0200 Message-ID: <4FDB9B9F.10709@profihost.ag> References: <4FDACD90.2080807@profihost.ag> <4FDB05A7.3080202@widodh.nl> <4FDB1DCC.6090701@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:56173 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757589Ab2FOUb0 (ORCPT ); Fri, 15 Jun 2012 16:31:26 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Sage Weil Cc: Mark Nelson , Wido den Hollander , "ceph-devel@vger.kernel.org" Am 15.06.2012 18:30, schrieb Sage Weil: > On Fri, 15 Jun 2012, Mark Nelson wrote: >> On 06/15/2012 04:51 AM, Wido den Hollander wrote: >> I think at some point someone mentioned to me that the mon can cause a lot of >> syncs, so running them on the OSDs without syncfs might be detrimental. For >> the majority of our internal performance testing I've kept them off the OSDs >> just to be sure. > > Right. The only thing interesting about the mon access pattern is that it > calls fsync() a lot when healthy, and will call syncfs() or sync() during > recovery. But if i have syncfs support does it still matter if they sit on an osd with a seperate disk? Do you have any iops or bandwith knowledge for the mon daemon? Stefan