From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38944) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1K05-00058q-4F for qemu-devel@nongnu.org; Wed, 17 Dec 2014 14:11:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y1Jzz-0003zx-Sg for qemu-devel@nongnu.org; Wed, 17 Dec 2014 14:11:09 -0500 Received: from indium.canonical.com ([91.189.90.7]:46432) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y1Jzz-0003zn-Mb for qemu-devel@nongnu.org; Wed, 17 Dec 2014 14:11:03 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.76 #1 (Debian)) id 1Y1Jzy-0001U7-TU for ; Wed, 17 Dec 2014 19:11:02 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id DBEAB2E8074 for ; Wed, 17 Dec 2014 19:11:02 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Wed, 17 Dec 2014 19:02:37 -0000 From: Serge Hallyn <1025244@bugs.launchpad.net> Sender: bounces@canonical.com References: <20120716123031.26191.29124.malonedeb@chaenomeles.canonical.com> <20141216125112.30835.26875.malone@chaenomeles.canonical.com> Message-Id: <20141217190237.GF32218@ubuntumail> Errors-To: bounces@canonical.com Subject: Re: [Qemu-devel] [Bug 1025244] Re: qcow2 image increasing disk size above the virtual limit Reply-To: Bug 1025244 <1025244@bugs.launchpad.net> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org @Mario, the external snapshots have apparently been around a long time. The ability to create external snapshots from running vms is newer, but it appears to exist evn in qemu-kvm 1.0. So all versions in Debian and Ubuntu should support them. http://wiki.qemu.org/Features/Snapshots#Snapshot_command_flow -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1025244 Title: qcow2 image increasing disk size above the virtual limit Status in QEMU: New Status in qemu-kvm package in Ubuntu: Triaged Bug description: Using qemu/kvm, qcow2 images, ext4 file systems on both guest and host Host and Guest: Ubuntu server 12.04 64bit To create an image I did this: qemu-img create -f qcow2 -o preallocation=3Dmetadata ubuntu-pdc-vda.img 1= 0737418240 (not sure about the exact bytes, but around this) ls -l ubuntu-pdc-vda.img fallocate -l theSizeInBytesFromAbove ubuntu-pdc-vda.img The problem is that the image is growing progressively and has obviously no limit, although I gave it one. The root filesystem's image is the same case: qemu-img info ubuntu-pdc-vda.img image: ubuntu-pdc-vda.img file format: qcow2 virtual size: 10G (10737418240 bytes) disk size: 14G cluster_size: 65536 and for confirmation: du -sh ubuntu-pdc-vda.img 15G ubuntu-pdc-vda.img I made a test and saw that when I delete something from the guest, the re= al size of the image is not decreasing (I read it is normal). OK, but when = I write something again, it doesn't use the freed space, but instead grows = the image. So for example: 1. The initial physical size of the image is 1GB. 2. I copy 1GB of data in the guest. It's physical size becomes 2GB. 3. I delete this data (1GB). The physical size of the image remains 2GB. 4. I copy another 1GB of data to the guest. 5. The physical size of the image becomes 3GB. 6. And so on with no limit. It doesn't care if the virtual size is less. Is this normal - the real/physical size of the image to be larger than the virtual limit??? To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1025244/+subscriptions