From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from detritus.pyropus.ca ([64.5.53.58]:52861 "HELO detritus.pyropus.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751637AbaLYDO3 (ORCPT ); Wed, 24 Dec 2014 22:14:29 -0500 Date: Wed, 24 Dec 2014 21:18:47 -0600 From: Charles Cazabon To: btrfs list Subject: Re: Oddly slow read performance with near-full largish FS Message-ID: <20141225031847.GC5864@pyropus.ca> References: <20141217024228.GA5544@pyropus.ca> <54955624.5040808@pobox.com> <20141221163207.GA18988@pyropus.ca> <54973C65.6070709@pobox.com> <54977E50.7000109@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <54977E50.7000109@jp.fujitsu.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Satoru Takeuchi wrote: > > In addition, to confirm whether this problem is caused only by > Btrfs or not, the following way can be used. > > 1. preparing the extra storage, > 2. copy Btrfs's data into int by dd if= of= > 3. Use it and confirm whether this problem still happen or not I've already copied the ~16TB of data from the btrfs filesystem to an XFS filesystem. I do not see the performance variability under xfs that I see under btrfs. > However, since the size of your Btrfs is quite large, I guess you > can't do it. If you have such extra storage, you've already > embed it to Btrfs. Actually, I decided to move to xfs, at least for now. Apparently not many people are using btrfs with filesystems >15TB, so it seems I'm in more-or-less uncharted territory, at least according to the responses I've gotten when looking into this issue. Charles -- ----------------------------------------------------------------------- Charles Cazabon GPL'ed software available at: http://pyropus.ca/software/ -----------------------------------------------------------------------