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=-3.8 required=3.0 tests=BAYES_00, 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 400FDC433E0 for ; Wed, 3 Feb 2021 14:14:57 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A4BA264DF6 for ; Wed, 3 Feb 2021 14:14:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A4BA264DF6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55984 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l7Ivl-0004iP-Hn for qemu-devel@archiver.kernel.org; Wed, 03 Feb 2021 09:14:53 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41820) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l7IuS-0003BS-MD for qemu-devel@nongnu.org; Wed, 03 Feb 2021 09:13:32 -0500 Received: from indium.canonical.com ([91.189.90.7]:41050) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1l7IuP-00036P-SH for qemu-devel@nongnu.org; Wed, 03 Feb 2021 09:13:32 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1l7IuO-0007qm-7T for ; Wed, 03 Feb 2021 14:13:28 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 35B8E2E813C for ; Wed, 3 Feb 2021 14:13:28 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Wed, 03 Feb 2021 14:01:06 -0000 From: Thomas Huth <1810603@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Incomplete; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: eblake kwolf-redhat lennyhers th-huth X-Launchpad-Bug-Reporter: Lenny Helpline (lennyhers) X-Launchpad-Bug-Modifier: Thomas Huth (th-huth) References: <154670237006.5111.1505843603378488710.malonedeb@wampee.canonical.com> Message-Id: <161236086695.4102.16381846828352578631.malone@chaenomeles.canonical.com> Subject: [Bug 1810603] Re: QEMU QCow Images grow dramatically X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="3d7abcb776ec05aa0a89112accc21bf8b41dfc24"; Instance="production" X-Launchpad-Hash: 902ba0a8008953f143945e5169a54ace04a84ea7 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -65 X-Spam_score: -6.6 X-Spam_bar: ------ X-Spam_report: (-6.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1810603 <1810603@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The QEMU project is currently considering to move its bug tracking to anoth= er system. For this we need to know which bugs are still valid and which co= uld be closed already. Thus we are setting older bugs to "Incomplete" now. If you still think this bug report here is valid, then please switch the st= ate back to "New" within the next 60 days, otherwise this report will be ma= rked as "Expired". Or mark it as "Fix Released" if the problem has been sol= ved with a newer version of QEMU already. Thank you and sorry for the incon= venience. ** Changed in: qemu Status: New =3D> Incomplete -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1810603 Title: QEMU QCow Images grow dramatically Status in QEMU: Incomplete Bug description: I've recently migrated our VM infrastructure (~200 guest on 15 hosts) from vbox to Qemu (using KVM / libvirt). We have a master image (QEMU QCow v3) from which we spawn multiple instances (linked clones). All guests are being revert once per hour for security reasons. About 2 weeks after we successfully migrated to Qemu, we noticed that almost all disks went full across all 15 hosts. Our investigation showed that the initial qcow disk images blow up from a few gigabytes to 100GB and more. This should not happen, as we revert all VMs back to the initial snapshot once per hour and hence all changes that have been made to disks must be reverted too. We did an addition test with 24 hour time frame with which we could reproduce this bug as documented below. Initial disk image size (created on Jan 04): -rw-r--r-- 1 root root 7.1G Jan 4 15:59 W10-TS01-0.img -rw-r--r-- 1 root root 7.3G Jan 4 15:59 W10-TS02-0.img -rw-r--r-- 1 root root 7.4G Jan 4 15:59 W10-TS03-0.img -rw-r--r-- 1 root root 8.3G Jan 4 16:02 W10-CLIENT01-0.img -rw-r--r-- 1 root root 8.6G Jan 4 16:05 W10-CLIENT02-0.img -rw-r--r-- 1 root root 8.0G Jan 4 16:05 W10-CLIENT03-0.img -rw-r--r-- 1 root root 8.3G Jan 4 16:08 W10-CLIENT04-0.img -rw-r--r-- 1 root root 8.1G Jan 4 16:12 W10-CLIENT05-0.img -rw-r--r-- 1 root root 8.0G Jan 4 16:12 W10-CLIENT06-0.img -rw-r--r-- 1 root root 8.1G Jan 4 16:16 W10-CLIENT07-0.img -rw-r--r-- 1 root root 7.6G Jan 4 16:16 W10-CLIENT08-0.img -rw-r--r-- 1 root root 7.6G Jan 4 16:19 W10-CLIENT09-0.img -rw-r--r-- 1 root root 7.5G Jan 4 16:21 W10-ROUTER-0.img -rw-r--r-- 1 root root 18G Jan 4 16:25 W10-MASTER-IMG.qcow2 Disk image size after 24 hours (printed on Jan 05): -rw-r--r-- 1 root root 13G Jan 5 15:07 W10-TS01-0.img -rw-r--r-- 1 root root 8.9G Jan 5 14:20 W10-TS02-0.img -rw-r--r-- 1 root root 9.0G Jan 5 15:07 W10-TS03-0.img -rw-r--r-- 1 root root 10G Jan 5 15:08 W10-CLIENT01-0.img -rw-r--r-- 1 root root 11G Jan 5 15:08 W10-CLIENT02-0.img -rw-r--r-- 1 root root 11G Jan 5 15:08 W10-CLIENT03-0.img -rw-r--r-- 1 root root 11G Jan 5 15:08 W10-CLIENT04-0.img -rw-r--r-- 1 root root 19G Jan 5 15:07 W10-CLIENT05-0.img -rw-r--r-- 1 root root 14G Jan 5 15:08 W10-CLIENT06-0.img -rw-r--r-- 1 root root 9.7G Jan 5 15:07 W10-CLIENT07-0.img -rw-r--r-- 1 root root 35G Jan 5 15:08 W10-CLIENT08-0.img -rw-r--r-- 1 root root 9.2G Jan 5 15:07 W10-CLIENT09-0.img -rw-r--r-- 1 root root 41G Jan 5 15:08 W10-ROUTER-0.img -rw-r--r-- 1 root root 18G Jan 4 16:25 W10-MASTER-IMG.qcow2 You can reproduce this bug as follow: 1) create an initial disk image 2) create a linked clone 3) create a snapshot of the linked clone 4) revert the snapshot every X minutes / hours Due the described behavior / bug, our VM farm is completely down at the moment (as we run out of disk space on all host systems). A quick fix for this bug would be much appreciated. Host OS: Ubuntu 18.04.01 LTS Kernel: 4.15.0-43-generic Qemu: 3.1.0 libvirt: 4.10.0 Guest OS: Windows 10 64bit To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1810603/+subscriptions