From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.fusionio.com ([66.114.96.31]:34676 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751162Ab2JHQJg (ORCPT ); Mon, 8 Oct 2012 12:09:36 -0400 Date: Mon, 8 Oct 2012 12:09:33 -0400 From: Josef Bacik To: =?iso-8859-1?Q?Sw=E2mi?= Petaramesh CC: "linux-btrfs@vger.kernel.org" Subject: Re: BTRFS, getting darn slower everyday Message-ID: <20121008160933.GA2259@localhost.localdomain> References: <50714AC8.4010100@petaramesh.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" In-Reply-To: <50714AC8.4010100@petaramesh.org> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Sun, Oct 07, 2012 at 03:26:32AM -0600, Swâmi Petaramesh wrote: > Hi, > > I have 4 machines, all converted to BTRFS about 6 months ago, now all > running Ubuntu Quantal with kernel 3.5.0-17 > > The matter is that all these machines are now getting slower and slower > everyday, every disk access causing the disk to be 100% busy for long > periods, to the point that I'm now seriously considering migrating > everything back to ext4... > > From the start BTRFS was "not very fast", still satisfactory, but now it > becomes truly unusable. > > On one machine, I know have a typical complete boot time to a usable GUI > that is over 4 minutes, with the HD still very busy for a couple more > minutes afterwards, where it used to be around 35-40 seconds in ext4 ! > > Is there anything I could do to speed things back (without losing all my > snapshots or doubling the size of data on disk)...? > > I already had made the move back from BTRFS to ext4 about 18 months ago, > I found it had improved so was back to BTRFS, and I wouldn't have to > revert back again :-/ > > Any advice or help greatly appreciated. > Can you get sysrq+w when you are seeing slowness? Usually bootup slow times means you don't have space_cache enabled or your cache is being evicted for some reason, can you check dmesg after bootup for messages related to space cache? Thanks, Josef