From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.virtall.com ([46.4.129.203]:55694 "EHLO mail.virtall.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752580AbdKGFNz (ORCPT ); Tue, 7 Nov 2017 00:13:55 -0500 Received: from mail.virtall.com (localhost [127.0.0.1]) by mail.virtall.com (Postfix) with ESMTP id 14721104CEB7 for ; Tue, 7 Nov 2017 05:13:50 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) (Authenticated sender: tch@virtall.com) by mail.virtall.com (Postfix) with ESMTPSA for ; Tue, 7 Nov 2017 05:13:50 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Date: Tue, 07 Nov 2017 14:13:49 +0900 From: Tomasz Chmielewski To: linux-btrfs Subject: Re: how to run balance successfully (No space left on device)? In-Reply-To: References: <5ff267d206ae631e9d259eacacdf7924@wpkg.org> <19a1770cf67e63a84c3baeeb44af9e9a@wpkg.org> Message-ID: <64e4c4c4341f5880349a02cf57eb3ff7@wpkg.org> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 2017-10-31 23:18, Tomasz Chmielewski wrote: > On 2017-09-18 17:20, Tomasz Chmielewski wrote: >>>> # df -h /var/lib/lxd >>>> >>>> FWIW, standard (aka util-linux) df is effectively useless in a >>>> situation >>>> such as this, as it really doesn't give you the information you need >>>> (it >>>> can say you have lots of space available, but if btrfs has all of it >>>> allocated into chunks, even if the chunks have space in them still, >>>> there >>>> can be problems). >> >> I see here on RAID-1, "df -h" it shows pretty much the same amount of >> free space as "btrfs fi show": >> >> - "df -h" shows 105G free >> - "btrfs fi show" says: Free (estimated): 104.28GiB >> (min: 104.28GiB) >> >> >> >>> But chances are pretty good that one you get that patch integrated, >>> whether by integrating it yourself to what you have currently, or by >>> trying 4.14-rc1 or waiting until it hits release or stable, that bug >>> will >>> have been squashed! =:^) >> >> OK, will wait for 4.14. > > So I've tried to run balance with 4.14-rc6. I've also tried with 4.14-rc7 on a server which was failing with "no space left" - unfortunately, it's still failing: # time btrfs balance start /srv WARNING: Full balance without filters requested. This operation is very intense and takes potentially very long. It is recommended to use the balance filters to narrow down the scope of balance. Use 'btrfs balance start --full-balance' option to skip this warning. The operation will start in 10 seconds. Use Ctrl-C to stop it. 10 9 8 7 6 5 4 3 2 1 Starting balance without any filters. ERROR: error during balancing '/srv': No space left on device There may be more info in syslog - try dmesg | tail real 8731m13.424s user 0m0.000s sys 560m36.363s # dmesg -c (...) [546228.496902] BTRFS info (device sda4): relocating block group 297455845376 flags data|raid1 [546251.393541] BTRFS info (device sda4): found 107799 extents [546512.346360] BTRFS info (device sda4): found 107799 extents [546529.407077] BTRFS info (device sda4): relocating block group 296382103552 flags metadata|raid1 [546692.465746] BTRFS info (device sda4): found 35202 extents [546733.294172] BTRFS info (device sda4): found 2586 extents [546738.487556] BTRFS info (device sda4): relocating block group 295308361728 flags data|raid1 [546770.474409] BTRFS info (device sda4): found 140906 extents [547037.744023] BTRFS info (device sda4): found 140906 extents [547065.840993] BTRFS info (device sda4): 117 enospc errors during balance # btrfs fi df /srv Data, RAID1: total=2.46TiB, used=2.35TiB System, RAID1: total=32.00MiB, used=416.00KiB Metadata, RAID1: total=19.00GiB, used=12.92GiB GlobalReserve, single: total=512.00MiB, used=0.00B # btrfs fi show /srv Label: 'btrfs' uuid: 105b2e0c-8af2-45ee-b4c8-14ff0a3ca899 Total devices 2 FS bytes used 2.36TiB devid 1 size 2.63TiB used 2.48TiB path /dev/sda4 devid 2 size 2.63TiB used 2.48TiB path /dev/sdb4 # btrfs fi usage /srv Overall: Device size: 5.25TiB Device allocated: 4.96TiB Device unallocated: 302.00GiB Device missing: 0.00B Used: 4.72TiB Free (estimated): 268.66GiB (min: 268.66GiB) Data ratio: 2.00 Metadata ratio: 2.00 Global reserve: 512.00MiB (used: 0.00B) Data,RAID1: Size:2.46TiB, Used:2.35TiB /dev/sda4 2.46TiB /dev/sdb4 2.46TiB Metadata,RAID1: Size:19.00GiB, Used:12.92GiB /dev/sda4 19.00GiB /dev/sdb4 19.00GiB System,RAID1: Size:32.00MiB, Used:416.00KiB /dev/sda4 32.00MiB /dev/sdb4 32.00MiB Unallocated: /dev/sda4 151.00GiB /dev/sdb4 151.00GiB Tomasz Chmielewski https://lxadm.com