From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A46C2C2D0DB for ; Thu, 30 Jan 2020 19:58:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 797D220708 for ; Thu, 30 Jan 2020 19:58:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727089AbgA3T6l (ORCPT ); Thu, 30 Jan 2020 14:58:41 -0500 Received: from luna.lichtvoll.de ([194.150.191.11]:54215 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726514AbgA3T6l (ORCPT ); Thu, 30 Jan 2020 14:58:41 -0500 Received: from 127.0.0.1 (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.lichtvoll.de (Postfix) with ESMTPSA id 3E207A9785; Thu, 30 Jan 2020 20:58:39 +0100 (CET) From: Martin Steigerwald To: Chris Murphy Cc: David Sterba , Martin Raiber , linux-btrfs@vger.kernel.org Subject: Re: With Linux 5.5: Filesystem full while still 90 GiB free Date: Thu, 30 Jan 2020 20:58:38 +0100 Message-ID: <16325152.4fYaUy9WYm@merkaba> In-Reply-To: References: <112911984.cFFYNXyRg4@merkaba> <20200130171950.GZ3929@twin.jikos.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Authentication-Results: mail.lichtvoll.de; auth=pass smtp.auth=martin smtp.mailfrom=martin@lichtvoll.de Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Chris Murphy - 30.01.20, 20:31:40 CET: > > > Is that mount option sufficient? Or does it take a filtered > > > balance? > > > What's the most minimal balance needed? I'm hoping -dlimit=1 > > > > > > I can't figure out a way to trigger this though, otherwise I'd be > > > doing more testing. > > > > I haven't checked but I think the suggested workarounds affect > > statfs as a side effect. Also as the reservations are temporary, > > the numbers change again after a sync. > > Yeah I'm being careful to qualify to mortal users that any workarounds > are temporary and uncertain. I'm not even certain what the pattern > is, people with new file systems have hit it. A full balance seems to > fix it, and then soon after the problem happens again. I don't do any > balancing these days, for over a year now, so I wonder if that's why > I'm not seeing it. > > But yeah a small number of people are hitting it, but it also stops > any program that does a free space check (presumably using statfs). > > A more reliable/universal work around in the meantime is still useful; > in particular if it doesn't require changing mount options, or only > requires it temporarily (e.g. not added to /etc/fstab, where it can > be forgotten for the life of that system). I did not balance either. Except maybe for a very short time during holding trainings in order to show to people how it works. I never bought into balancing regularily. Thanks, -- Martin