From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: Re: 10 times higher disk load with btrfs Date: Mon, 05 Jan 2015 20:19:27 +0100 Message-ID: <54AAE3BF.9080908@profihost.ag> References: <54AAD9B5.5080207@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]:28417 "EHLO mail-ph.de-nserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753297AbbAETS6 (ORCPT ); Mon, 5 Jan 2015 14:18:58 -0500 In-Reply-To: <54AAD9B5.5080207@profihost.ag> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Am 05.01.2015 um 19:36 schrieb Stefan Priebe: > Hi devs, > > while btrfs is now declared as stable ;-) i wanted to retest btrfs on > our production cluster on 2 out of 54 osds. So if they crash it doesn't > hurt. > > While if those OSDs run XFS have spikes of 20MB/s every 4-7s. The same > OSDs after formatting them with btrfs have spikes of 190MB/s every 4-7s. > > Why does just another filesystem raises the disk load by a factor of 10? OK this seems to happen cause ceph is creating every 5s a new subvolume / snap. Is this really expected / needed? Stefan > > I'm running dumpling. > > Greets Stefan