From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mondschein.lichtvoll.de ([194.150.191.11]:34654 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755093Ab2LILUf (ORCPT ); Sun, 9 Dec 2012 06:20:35 -0500 Received: from merkaba.localnet (ppp-93-104-144-117.dynamic.mnet-online.de [93.104.144.117]) by mail.lichtvoll.de (Postfix) with ESMTPSA id 8F16E10A for ; Sun, 9 Dec 2012 12:19:16 +0100 (CET) From: Martin Steigerwald To: linux-btrfs@vger.kernel.org Subject: Re: How to refresh degraded BTRFS? free space fragmentation, file fragmentation... Date: Sun, 9 Dec 2012 12:20:33 +0100 References: <201212091212.26248.Martin@lichtvoll.de> (sfid-20121209_121802_607942_89B77E9F) In-Reply-To: <201212091212.26248.Martin@lichtvoll.de> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Message-Id: <201212091220.33609.Martin@lichtvoll.de> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Am Sonntag, 9. Dezember 2012 schrieb Martin Steigerwald: > Hi! > > I have BTRFS on some systems since more than two years. My experience so > far is: Performance at the beginning is pretty good, but some of my more > often used BTRFS filesystem degrade badly in different areas. On some > workloads pretty quickly. > > There are also some fs however that did not degrade that badly. These were > some that have way more free space left than the ones that degraded > badly. About 900 GB freespace left on my eSATA backup disk with BTRFS > that is also quite new. About 80 GB left on my BTRFS RAID 1 local home disk > where I can build debian packages or kernels and such without the restrictions > NFS brings (root squash). These still appear to be fine, but I redid the local > home one with mkfs.btrfs -n 32768 and -l 32768 not to long ago, but I > think it was quite fine before anyway, so I might have overdone it here. > This already points at a way to prevent some degradation BTRFS filesystems: > Leave more free space. I also do not use them regularily as in each day. Backup disk just every two weeks or so. Local home sometimes each day a week, then not at all for weeks. -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7