From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [195.159.176.226] ([195.159.176.226]:41856 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751169AbdLAVrY (ORCPT ); Fri, 1 Dec 2017 16:47:24 -0500 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1eKt9O-0004tx-Lw for linux-btrfs@vger.kernel.org; Fri, 01 Dec 2017 22:47:14 +0100 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: btrfs-transacti hammering the system Date: Fri, 1 Dec 2017 21:47:05 +0000 (UTC) Message-ID: References: <9703c200-28af-f26d-b3b2-6982fb289ac8@mendix.com> <1d11e03c-7d02-3f66-8b97-4c1b857566fa@techsquare.com> <5ecddad2-bb6a-2991-c8d0-be97a4541b0d@mendix.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: 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. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman