From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1HSc5w-00069I-Nh for qemu-devel@nongnu.org; Sat, 17 Mar 2007 12:49:28 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1HSc5u-000694-9W for qemu-devel@nongnu.org; Sat, 17 Mar 2007 12:49:27 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1HSc5u-000691-3Y for qemu-devel@nongnu.org; Sat, 17 Mar 2007 11:49:26 -0500 Received: from fmmailgate09.web.de ([217.72.192.184]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1HSc4e-0003ia-7f for qemu-devel@nongnu.org; Sat, 17 Mar 2007 12:48:08 -0400 Received: from web.de by fmmailgate09.web.de (Postfix) with SMTP id 24096510760 for ; Sat, 17 Mar 2007 17:48:07 +0100 (CET) Date: Sat, 17 Mar 2007 17:48:06 +0100 Message-Id: <1736908044@web.de> MIME-Version: 1.0 From: herbie hancock Subject: =?iso-8859-15?Q?Re:_[Qemu-devel]_QCOW(2)_image_corruption_under_QEMU_0?= =?iso-8859-15?Q?.9.0_reproducible?= Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: quoted-printable Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org > -----Urspr=FCngliche Nachricht----- > Von: qemu-devel@nongnu.org > Gesendet: 16.03.07 13:11:15 > An: qemu-devel@nongnu.org > Betreff: Re: [Qemu-devel] QCOW(2) image corruption under QEMU 0.9.0 repr= oducible > herbie hancock wrote: > > Hello, i had also a reproducible disk crash: > > info of the last good image, size is about 3,5GB > >=20 > > I never experienced such a bad problem with qemu before, maybe it is a= problem with qcow2 format =3F >=20 > After the problems with qcow2 images which I reported here a few weeks > ago, I've only been using qcow images (under QEMU 0.9.0), without such > surprises. So it seems qemu has some bug related to qcow2 images, > maybe manifesting itself only after they get larger than 4GB... >=20 >=20 > Best regards > J Esteves >=20 >=20 > =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://lists.nongnu.org/mailman/listinfo/qemu-devel >=20 I am quite sure now that it is a problem with the qcow2 format.=20 I can reprodue the bug only on a qcow2 image. I did a disk fill test with = dd on a qcow2 Image and the same test on a qcow Image,=20 both images had the same content. (Image 16GB Debian 4.0 Etch, hda1 ext3 = 15 gb, hda5 swap 700MB) The qcow2 Image was totally corrupted and is not bootable any more, the qc= ow Image passed the tests without any errors Host system was now winxp sp2 instead of win2k, so i dont think its a pro= blem of the host os. I think a big warning for the users is necessary that they should work wi= th qcow instead of qcow2 until the bug is fixed Best regards hr Test Setup: --------------- Made a copy of the last known good qcow2 image (size 3.3 GB) and converted= it to qcow ..\QemuManager\qemu\qemu-img.exe convert debian4=5F0.dsk -O qcow debian4=5F0=5Fq= cow.dsk Crashtest with debian4=5F0.dsk (qcow2 format) ----------------------------------------------------------- Size of intact debian4=5F0.dsk 3.551.580.160 Bytes file format: qcow2 virtual size: 16G (16777216000 bytes) disk size: 3.3G cluster=5Fsize: 4096 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 test 79M 2007-03-11 18:34:49 00:07:47.475 Start VM: I:\debian4.0\QemuManager\qemu\qemu.exe -L "I:\debian4.0\QemuMana= ger\qemu" -m 256 -hda "I:\debian4.0\debian4\debian4=5F0.dsk" -cdrom "I:\debi= an4.0\debian4\debian-testing-i386-DVD-1.iso" -kernel-kqemu -net nic,vlan=3D0= -net user,vlan=3D0 -std-vga -localtime fsck on mounted filesystem: fsck -nv /dev/hda1 show no errors except # of = free inodes df 19% of system used (Total: 15409468 used: 2641020) fill the rest of the disk: dd if=3D/dev/zero of=3D/tmp/bigfile bs=3D16M dd stops with disk full, ok ---> now fsck -nv /dev/hda1 shows endless output of errors <----- ER= ROR rm bigfile shutdown system did work ---> Restart VM: Fatal not a bootable harddisk ext3 is totally corrupt = <------- ERROR In this case there was no crash on the VM, as i had on WIN2K, header of th= e image file seems to be still intact Info after crash: image: debian4=5F0.dsk file format: qcow2 virtual size: 16G (16777216000 bytes) disk size: 16G <---- 16GB (why so much on a 15GB Partition =3F) cluster=5Fsize: 4096 Snapshot list: ID TAG VM SIZE DATE VM CLOCK 1 test 79M 2007-03-11 18:34:49 00:07:47.475 Size of crashed debian4=5F0.dsk 16.659.554.304 Bytes Test with debian4=5F0=5Fqcow.dsk: ------------------------------------------ Size of debian4=5F0=5Fqcow.dsk: 3.105.832.960 Bytes image: debian4=5F0=5Fqcow.dsk file format: qcow virtual size: 16G (16777216000 bytes) disk size: 2.9G cluster=5Fsize: 4096 Start VM: I:\debian4.0\QemuManager\qemu\qemu.exe -L "I:\debian4.0\QemuMana= ger\qemu" -m 256 -hda "I:\debian4.0\debian4\debian4=5F0=5Fqcow.dsk" -cdrom "I:= \debian4.0\debian4\debian-testing-i386-DVD-1.iso" -kernel-kqemu -net nic,v= lan=3D0 -net user,vlan=3D0 -std-vga -localtime fsck on mounted filesystem: fsck -nv /dev/hda1 show no errors except # of = free inodes df 19% of system used (Total: 15409468 used: 2641020) fill the rest of the disk: dd if=3D/dev/zero of=3D/tmp/bigfile bs=3D16M dd stops with disk full, ok now fsck -nv /dev/hda1 no errors rm bigfile shutdown system did work image: debian4=5F0=5Fqcow.dsk file format: qcow virtual size: 16G (16777216000 bytes) disk size: 15G cluster=5Fsize: 4096 Size of debian4=5F0=5Fqcow.dsk: 15.919.493.120 Bytes Start VM: all o.k. ----------------------------------------------------- =5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F Viren-Scan f=FCr Ihren PC! Jetzt f=FCr jeden. Sofort, online und kostenlos. Gleich testen! http://www.pc-sicherheit.web.de/freescan/=3Fmc=3D022222