Red Hat Bugzilla – Full Text Bug Listing
|Summary:||KVM guest ext3 errors at shutdown when using virtio and a qcow2 backing file|
|Product:||[Fedora] Fedora||Reporter:||Tom Horsley <horsley1953>|
|Component:||qemu||Assignee:||Mark McLoughlin <markmc>|
|Status:||CLOSED RAWHIDE||QA Contact:||Fedora Extras Quality Assurance <extras-qa>|
|Version:||rawhide||CC:||berrange, chellwig, dwmw2, gcosta, itamar, jaswinder, jforbes, kwolf, markmc, quintela, virt-maint|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2009-10-12 03:16:26 EDT||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Bug Depends On:|
Description Tom Horsley 2009-09-21 19:55:38 EDT
Created attachment 362017 [details] screenshot of the froze up shutdown screen Description of problem: I finally got my ubuntu KVM to run under rawhide's virt-manager, so decided to try qcow2 again, converting my raw disk image file to qcow2 to save as a common base image, then using it as the base of another qcow2 file to run the KVM with. All seemed well, working much better than it did when I tried the same thing in fedora 11, but then I ran shutdown -h now in the KVM, and it spewed a batch of errors about problems with journal as it was shutting down and hung. Version-Release number of selected component (if applicable): qemu-img-0.10.92-4.fc12.x86_64 qemu-system-x86-0.10.92-4.fc12.x86_64 qemu-common-0.10.92-4.fc12.x86_64 qemu-kvm-0.10.92-4.fc12.x86_64 gpxe-roms-qemu-0.9.7-5.fc12.noarch How reproducible: Only tried it once. Steps to Reproduce: 1.see above. 2. 3. Actual results: hang at shutdown with journal errors Expected results: clean shutdown Additional info:
Comment 1 Tom Horsley 2009-09-23 18:59:28 EDT
I've now tried this a few more times, and continued to get errors with the disk using virtio (not always the journal errors above, sometimes it would hang at boot or flake out randomy in other ways). I converted the disk to use an emulated ide mode such as is used by default with windows xp, and the problems all disappeared. I should probably add that I was using kernel 2.6.31-33.fc12.x86_64 for all this testing, and I have a 4 processor machine with the ubuntu KVM also set to use 4 vcpus.
Comment 2 Mark McLoughlin 2009-10-01 04:56:47 EDT
Tom: could you give us more details about the guest? Could you also supply /var/log/libvirt/qemu/$guest.log ? Perhaps also worth trying Fedora 11 and Fedora 12 guests hch, kwolf: any ideas on this? sounds like it only happens with qcow2+virtio. My guess is that no cache= parameter is supplied
Comment 3 Tom Horsley 2009-10-01 06:00:22 EDT
I'll give it another try to get a log, but I'm pretty sure I remember looking in the log when it happened and the only thing in it was the initial qemu-kvm command line - no messages after that. The guest is 64 bit ubuntu 9.04 installed via the "alternate" text based installer iso image.
Comment 4 Tom Horsley 2009-10-01 08:30:27 EDT
Also, this may be something silly I did wrong. I only recently managed to discover the deeply nested, jargon camouflaged, dialog in virt-manager that would let me create a qcow2 image at install time, so this qcow2 image is really the result of used qemu-img to convert the raw image I got in initial install to a qcow2 image. I didn't change any parameters in the xml definition of the storage for the virtual machine, I just made the file it referred to be a qcow2 image. If changes to other attributes were required, they didn't happen (though I did sort of assume it ought to recognize the image format and do whatever was necessary automagically).
Comment 5 Mark McLoughlin 2009-10-01 09:13:07 EDT
Tom: it's always best to include the guest XML config and log file, so we can spot whether the config is correct If you have: <disk type='file' device='disk'> <driver name='qemu' type='raw'/> then you need to change it to: <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> but I assume you don't have the <driver> line at all You could try making it: <disk type='file' device='disk'> <driver name='qemu' type='qcow2' cache='none'/> and see if that helps
Comment 6 Tom Horsley 2009-10-01 22:16:40 EDT
OK, I've narrowed it down. What I really need to make it fail is not just a single qcow2 image but a qcow2 image with another qcow2 image backing it up. I reinstalled (running on a rawhide system) a new ubuntu image from scratch, this time using a qcow2 image in the initial install by diving down into the use existing storage button and creating one in there. That image worked fine with all the virt-manager created defaults. The disk definition looked like: <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/var/lib/libvirt/images/u2.img.img'/> <target dev='vda' bus='virtio'/> </disk> But then I shutdown the machine, and diddled the disk images to rename the original image and make a new image based on it, so that I had this combination: [root@zooty images]# ls -l u2* -r--r--r-- 1 root root 2801205248 2009-10-01 21:42 u2-base.img -rw-rw-rw- 1 root root 6946816 2009-10-01 22:04 u2.img.img [root@zooty images]# qemu-img info u2-base.img image: u2-base.img file format: qcow2 virtual size: 20G (20971520000 bytes) disk size: 2.6G cluster_size: 65536 [root@zooty images]# qemu-img info u2.img.img image: u2.img.img file format: qcow2 virtual size: 20G (20971520000 bytes) disk size: 6.5M cluster_size: 65536 backing file: u2-base.img (actual path: u2-base.img) Now when I boot the kvm, it randomly fails, sometimes during boot, sometimes later. Adding cache='none' does not change this behavior, I still get random failures. However, if I change the disk device to look like this: <disk type='file' device='disk'> <source file='/var/lib/libvirt/images/ubu.img.img'/> <target dev='hda' bus='ide'/> </disk> then everything works perfectly fine, even with the qcow2 based on another qcow2.
Comment 7 Tom Horsley 2009-10-01 22:20:06 EDT
Created attachment 363413 [details] The xml definition for the new "u2" ubuntu machine Here's the current incarnation of the xml definition. This one has the cache=none attribute (which didn't help).
Comment 8 Tom Horsley 2009-10-01 22:29:53 EDT
Created attachment 363416 [details] The qemu log file for the u2 virtual machine Nothing much in here but qemu command lines, but I add it for completeness.
Comment 9 Mark McLoughlin 2009-10-02 04:12:23 EDT
Great stuff, Tom - thanks Christoph: summary seems to be that this is specific to virtio and qcow2 with a backing file
Comment 10 Mark McLoughlin 2009-10-06 11:32:24 EDT
Kevin is looking at this, I think
Comment 11 Mark McLoughlin 2009-10-09 03:41:42 EDT
http://lists.gnu.org/archive/html/qemu-devel/2009-10/msg00767.html Kevin, it sounds like Anthony is fine with this patch for the stable branch, so I'll go ahead and pull it into F-12 today
Comment 12 Kevin Wolf 2009-10-09 03:55:48 EDT
I was going to ask you to apply it today, but you're just too quick for me. :-) Yes, please do. It's the only sane thing we can do for a code base that will be used by real users soon.
Comment 13 Mark McLoughlin 2009-10-09 10:36:13 EDT
* Fri Oct 9 2009 Mark McLoughlin <email@example.com> - 2:0.11.0-6 - Fix fs errors with virtio and qcow2 backing file (#524734) - Fix ksm initscript errors on kernel missing ksm (#527653) - Add missing Requires(post): getent, useradd, groupadd (#527087)
Comment 14 Mark McLoughlin 2009-10-09 12:01:59 EDT
tag request: https://fedorahosted.org/rel-eng/ticket/2429
Comment 15 Mark McLoughlin 2009-10-12 03:16:26 EDT
tagged now for F12 GA