From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: Re: how to debug slow rbd block device Date: Tue, 22 May 2012 22:54:12 +0200 Message-ID: <4FBBFCF4.5060905@profihost.ag> References: <4FBB8A5B.9010500@profihost.ag> <4FBBEBC8.1000205@profihost.ag> <1C70F3FB753C4AEC97247E04FAE3C733@inktank.com> <4FBBF74C.9020608@profihost.ag> <4FBBFBA5.9090604@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:47519 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760409Ab2EVUyP (ORCPT ); Tue, 22 May 2012 16:54:15 -0400 In-Reply-To: <4FBBFBA5.9090604@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Mark Nelson Cc: ceph-devel@vger.kernel.org Am 22.05.2012 22:48, schrieb Mark Nelson: > Can you use something like iostat or collectl to check and see if the > write throughput to each SSD is roughly equal during your tests? It is but just around 20-40MB/s. But they can write 260MB/s with sequential writes. > Also, what FS are you using and how did you format/mount it? just: mkfs.xfs /dev/sdb1 mount options: noatime,nodiratime,nobarrier,discard Stefan