From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:36573 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751823Ab2JHQqO (ORCPT ); Mon, 8 Oct 2012 12:46:14 -0400 Received: by mail-bk0-f46.google.com with SMTP id jk13so2170500bkc.19 for ; Mon, 08 Oct 2012 09:46:13 -0700 (PDT) Message-ID: <5073035F.6000600@gmail.com> Date: Mon, 08 Oct 2012 18:46:23 +0200 From: Goffredo Baroncelli MIME-Version: 1.0 To: =?ISO-8859-1?Q?Sw=E2mi_Petaramesh?= CC: linux-btrfs@vger.kernel.org Subject: Re: BTRFS, getting darn slower everyday References: <50714AC8.4010100@petaramesh.org> <50718151.8090506@petaramesh.org> <201210071644.19815.Martin@lichtvoll.de> <5072066B.4020604@gmail.com> <50726DE1.20101@petaramesh.org> <5072F63B.5060608@petaramesh.org> In-Reply-To: <5072F63B.5060608@petaramesh.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 10/08/2012 05:50 PM, Swâmi Petaramesh wrote: > Hi again Goffredo, > > Le 08/10/2012 13:38, Goffredo Baroncelli a écrit : >> I fear that both the combination of autodefrag and the high number of >> snapshot could be the root-cause of the the bad performance. > I've removed, on one of my machines, all snapshots but three per subvol > (keeping the oldests and newest), going from about 30 per subvol to 3, > for the complete filesystem from 120+ to about a dozen. > > Then I let btrfs-cleaner do its job > > After that the machine boots to GUI in a bit less than 2 minutes, where > it was more than 4 minutes previously. > > The machine now seems much more reactive and swift. > > So it seems that the number or active snapshots (or is it the number of > subvols whatsoever ??) dramatically impacts performance... Does the autodefrag options still alive ? I believe that the snapshot is quite cheap, except if you update the shared files one at time. Which should be the case of the autodefrag. But it is only a my supposition.... Could you please try to avoid the autodefrag option in a machine with an high number of snapshot ? I am curios... > > Thanks for the suggestion. >