From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:63786 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751625AbaEHQLF (ORCPT ); Thu, 8 May 2014 12:11:05 -0400 Message-ID: <536BAC5F.60803@fb.com> Date: Thu, 8 May 2014 12:10:07 -0400 From: Josef Bacik MIME-Version: 1.0 To: , Btrfs BTRFS Subject: Re: Balance performance problem with 3.14.1 References: <201405081950.23922.russell@coker.com.au> In-Reply-To: <201405081950.23922.russell@coker.com.au> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 05/08/2014 05:50 AM, Russell Coker wrote: > I've got a server/workstation (KDE desktop and file server) running kernel > 3.14.1 from the Debian package 3.14-trunk-amd64. > > It was running well until I decided to do a full balance of the BTRFS RAID-1 > array of 3TB SATA disks (which hadn't been balanced before due to previous > kernels performing badly with scrub or balance). I canceled the balance after > about 5 days when it had been claiming to be about 65% done for a day while > doing a lot of disk IO. > Can I see dmesg/messages for the time that this was running for so long? > After canceling the balance the performance of the array has been poor. It > has a cron job that runs twice a week to rsync data from a Maildir based mail > server that currently has 2401473 Inodes in use according to ZFS on the mail > server (unfortunately BTRFS won't tell me how many Inodes are in use). The > cron job does an "rsync -va" type backup WITHOUT the -c option, so we're > basically doing a recursive stat on all files and then transferring new files > (Dovecot index files are excluded so files tend never to change). After the > rsync is complete "cp -rl" is used to make a backup of the tree. > > The cp -rl usually takes something less than 30 minutes (not long enough for > me to even notice) but today cp has been running for 5.5 hours and seems to be > about 3/5 done (9000/15000 subdirectories linked). > Sysrq+w while it's running, just one and then wait a while and then another. Thanks, Josef