From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aquinas.techsquare.com ([75.125.237.226]:41194 "EHLO techsquare.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751031AbdLAVvE (ORCPT ); Fri, 1 Dec 2017 16:51:04 -0500 To: Duncan <1i5t5.duncan@cox.net>, linux-btrfs@vger.kernel.org References: <9703c200-28af-f26d-b3b2-6982fb289ac8@mendix.com> <1d11e03c-7d02-3f66-8b97-4c1b857566fa@techsquare.com> <5ecddad2-bb6a-2991-c8d0-be97a4541b0d@mendix.com> From: Matt McKinnon Message-ID: <113cba02-2557-d1e8-193f-fab4437f1199@techsquare.com> Date: Fri, 1 Dec 2017 16:50:59 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Subject: Re: btrfs-transacti hammering the system Sender: linux-btrfs-owner@vger.kernel.org List-ID: Well, it's at zero now... # btrfs fi df /export/ Data, single: total=30.45TiB, used=30.25TiB System, DUP: total=32.00MiB, used=3.62MiB Metadata, DUP: total=66.50GiB, used=65.16GiB GlobalReserve, single: total=512.00MiB, used=0.00B On 01/12/17 16:47, Duncan wrote: > Hans van Kranenburg posted on Fri, 01 Dec 2017 18:06:23 +0100 as > excerpted: > >> On 12/01/2017 05:31 PM, Matt McKinnon wrote: >>> Sorry, I missed your in-line reply: >>> >>> >>>> 2) How big is this filesystem? What does your `btrfs fi df >>>> /mountpoint` say? >>>> >>> >>> # btrfs fi df /export/ >>> Data, single: total=30.45TiB, used=30.25TiB >>> System, DUP: total=32.00MiB, used=3.62MiB >>> Metadata, DUP: total=66.50GiB, used=65.08GiB >>> GlobalReserve, single: total=512.00MiB, used=53.69MiB >> >> Multi-TiB filesystem, check. total/used ratio looks healthy. > > Not so healthy, from here. Data/metadata are healthy, yes, > but... > > Any usage at all of global reserve is a red flag indicating that > something in the filesystem thinks, or thought when it resorted > to global reserve, that space is running out. > > Global reserve usage doesn't really hint what the problem is, > but it's definitely a red flag that there /is/ a problem, and > it's easily overlooked, as it apparently was here. > > It's likely indication of a bug, possibly one of the ones fixed > right around 4.12/4.13. I'll let the devs and better experts take > it from there, but I'd certainly be worried until global reserve > drops to zero usage. >