From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Spray Subject: Re: Slow file creating and deleting using bonnie ++ on Hammer Date: Tue, 26 May 2015 12:57:23 +0100 Message-ID: <55645FA3.3090507@redhat.com> References: <555F4C78.7060601@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60906 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754241AbbEZNuf (ORCPT ); Tue, 26 May 2015 09:50:35 -0400 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "Yan, Zheng" , Barclay Jameson Cc: Gregory Farnum , "ceph-devel@vger.kernel.org" On 26/05/2015 07:55, Yan, Zheng wrote: > the reason for slow file creations is that bonnie++ call fsync(2) > after each creat(2). fsync() wait for safe replies of the create > requests. MDS sends safe reply when log event for the request gets > journaled safely. MDS flush the journal every 5 seconds > (mds_tick_interval). So the speed of file creation for bonnie++ is one > file every file seconds. Ah, I hadn't noticed that the benchmark called... I wonder if I'm seeing the fuse client return quickly because it simply doesn't implement the fsyncdir call. We should fix that! It looks like we used to have an OP_FSYNC in the client-server protocol (perhaps for flushing the log immediately on fsyncs), anyone have any background on why that went away? Cheers, John