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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 16429C432C0 for ; Fri, 22 Nov 2019 12:31:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF50120714 for ; Fri, 22 Nov 2019 12:31:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Qspac2Ml" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727184AbfKVMbZ (ORCPT ); Fri, 22 Nov 2019 07:31:25 -0500 Received: from mail-ed1-f47.google.com ([209.85.208.47]:46323 "EHLO mail-ed1-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726620AbfKVMbZ (ORCPT ); Fri, 22 Nov 2019 07:31:25 -0500 Received: by mail-ed1-f47.google.com with SMTP id t11so5829862eds.13 for ; Fri, 22 Nov 2019 04:31:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=gNEwLYEfnvGE3N+gNR/JXkQeN41x/z7GXrxFMRzu9E8=; b=Qspac2MlMyU95PQsSUpLWh/inohZKBuMMTXvM8azuyC4WcvyWETjfBcpYj8OhXmnTa axuTYTcKH7AqFKzMJOg1r62/vDzjjFPfgjNFBQdPpWgOaKCjek5psRyioHLrt7vNh/Cb NIth02BDEitGvb2CpnEOupAiNIUtjvKCzO+1ynpD7tGAXNdbNSSs7UCKtBWgWkRcBhog nu++Ee/IpzbQmuUQT5SGJFKQtHigsNSPUq7CZ3s6YKJs+puhoMV0+7BM3q/xUgmLyq3H 1Zy66t+srRHSZmzy0i/vuDfjdK8x4EVYzhg2bg2kblhwYYYoNG4lPnWesZeeIJRLnS1H PlGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=gNEwLYEfnvGE3N+gNR/JXkQeN41x/z7GXrxFMRzu9E8=; b=Zc9UfUUZQOPblz9FqzGMKBxCahPOsukU7KFCoiH/t3InYgM3dkqUrHGp6C/nNQZQtD Dy1NETXC/+ffmBtWUkQS8OFHKETXzCwfoFvO+haj5Jhd0hQzPwqQHtSfx10C8C/4DRkG HuSJxsIRQc5FL/c7zoy8GbPVukhSumAlnZSbPUInrvBWXq1z+c1SkBX556SQN8f+Zt36 Scuzz1U2yEL5rSnGt03BLl5OXSI9ahvzQT0ktaH/jQ2qXH023aXyMscdvhR+4udXWcWf 03BDUUPJGpiN5+hVvP+nUwB+P3dq5G9GvnD2zgNMwDFUMmd6RMl4E698ohzyX4Xw4RPr lTUQ== X-Gm-Message-State: APjAAAViDJHYeWxs96n+d0auOifYj+KrPZRZQ8KAAyilV8BIHD/Rsv8d 5d0IN/y6LHB5ECLVIk8/TVkDCnFEqK7DfbSFikQPEhw= X-Google-Smtp-Source: APXvYqzOdLMAkHAxMq7BZEL8E+GeBfgp7Murl3fGCWus+IOhYKy0tJYS8DR1eAOkYv0Ct/B6WbvWQQZ9Mn+s9t1YEJ4= X-Received: by 2002:a17:906:b25a:: with SMTP id ce26mr21689602ejb.13.1574425883010; Fri, 22 Nov 2019 04:31:23 -0800 (PST) MIME-Version: 1.0 References: <20191112183425.GA1257@tik.uni-stuttgart.de> <7f628741-b32e-24dc-629f-97338fde3d16@googlemail.com> <3e5cd446-3527-17ef-9ab8-d6ad01d740d0@gmx.com> <4544ecff-b70e-09fb-6fd3-e2c03d848c1c@googlemail.com> <2b0f68d6-6d27-2f14-0b44-8a40abad6542@googlemail.com> In-Reply-To: <2b0f68d6-6d27-2f14-0b44-8a40abad6542@googlemail.com> From: Christian Pernegger Date: Fri, 22 Nov 2019 13:30:46 +0100 Message-ID: Subject: Re: freezes during snapshot creation/deletion -- to be expected? (Was: Re: btrfs based backup?) To: linux-btrfs Content-Type: text/plain; charset="UTF-8" Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Am Fr., 22. Nov. 2019 um 00:57 Uhr schrieb Oliver Freyermuth : > > 2) I'm wondering if this couldn't be improved. [...] > > You can check e.g. the man page btrfs-quota(8) for a short discussion on why doing quota correctly > with btrfs is not as easy as it may seem. I've read that and I appreciate the difficulties in getting accurate usage information (or even defining what that means) from a COW filesystem. IMHO, performance, and the trade-off between performance and up-to-the-minute accuracy are separate issues. FWIW, running btrfs quota disable, enable, and rescan got rid of the orphan qgroups. The full rescan ran for all of 3 seconds and didn't block. Cheers, C.