From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mondschein.lichtvoll.de ([194.150.191.11]:44496 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933764Ab2LIKNr convert rfc822-to-8bit (ORCPT ); Sun, 9 Dec 2012 05:13:47 -0500 From: Martin Steigerwald To: linux-btrfs@vger.kernel.org Subject: Re: BTRFS, getting darn slower everyday Date: Sun, 9 Dec 2012 11:13:45 +0100 Cc: Jan Engelhardt , =?iso-8859-1?q?Sw=E2mi_Petaramesh?= References: <50714AC8.4010100@petaramesh.org> <201210071648.54027.Martin@lichtvoll.de> (sfid-20121209_110802_169559_532F2DD4) In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Message-Id: <201212091113.45283.Martin@lichtvoll.de> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Am Sonntag, 9. Dezember 2012 schrieb Jan Engelhardt: > On Sunday 2012-10-07 16:48, Martin Steigerwald wrote: > >> > >> # btrfs su li / > >> ID 256 top level 5 path UBUNTU > >> ID 259 top level 5 path UBUNTU/@ > >> ID 261 top level 5 path UBUNTU/@tmp > >> ID 262 top level 5 path UBUNTU/@home > >>[...] > > > >This could be 100 or more subvolumes / snapshots. > >Maybe slowness could be related to this one. > > Absolutely. COW snapshots cause severe fragmentation (it's > in their nature). "Easily" reproducible by snapshotting an fs > every day. Been there, had that. So such a workload is only possible with pleasing speed with SSD? I have about 5-10 snapshots on my backup 2TB eSATA disk which I currently rsync to. This seems to work quite well still. But I have no idea how that would turn out with 100 snapshots or more. And about 1 TB is free, so at least IŽd expect no serious freespace fragmentation like on the BTRFS in my SSD (extra post for that one). Ciao, -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7