Red Hat Bugzilla – Bug 1160084
domfsfreeze and domfsthaw cannot work well when guest restart
Last modified: 2015-03-05 02:46:47 EST
Description of problem: domfsfreeze and domfsthaw cannot work well when guest restart Version-Release number of selected component (if applicable): libvirt-1.2.8-5.el7.x86_64 qemu-kvm-rhev-2.1.2-4.el7.x86_64 How reproducible: 100% Steps to Reproduce: 1.prepare a guest with agent # virsh dumpxml test3 <channel type='unix'> <source mode='bind' path='/var/lib/libvirt/qemu/r6-7.agent'/> <target type='virtio' name='org.qemu.guest_agent.0'/> <alias name='channel0'/> <address type='virtio-serial' controller='0' bus='0' port='8'/> </channel> 2.# virsh start test3 Domain test3 started 3.# virsh domfsfreeze test3 Froze 1 filesystem(s) 4.restart guest # virsh destroy test3 Domain test3 destroyed # virsh start test3 Domain test3 started 5.guest will cannot be used domfsfreeze # virsh domfsfreeze test3 error: Unable to freeze filesystems error: Requested operation is not valid: domain is already quiesced 6.use domfsthaw # virsh domfsthaw test3 Thawed 0 filesystem(s) 7.guest's fs can be froze again # virsh domfsfreeze test3 Froze 1 filesystem(s) Actual results: guest's fs cannot be Froze after destroy and restart it. Expected results: After restart guest we can use domfsfreeze normal Additional info: Also found issue when use command reset migrate
Patch proposed upstream: https://www.redhat.com/archives/libvir-list/2014-November/msg00022.html
Moving to POST: http://post-office.corp.redhat.com/archives/rhvirt-patches/2014-November/msg00959.html
During verify this bug, i found domfsfreeze cannot work well with save, managedsasve, migrate. 1.# virsh domfsfreeze test3 Froze 1 filesystem(s) 2.# virsh managedsave test3 Domain test3 state saved by libvirt 3.# virsh start test3 Domain test3 started 4.# virsh domfsfreeze test3 error: Unable to freeze filesystems error: internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': The command guest-fsfreeze-freeze has been disabled for this instance 5.# virsh domfsfreeze test3 Froze 1 filesystem(s) And i check the guest status via virt-manager, the guest fs is still freezed after restore it, but i can do domfsfreeze to it and get a error, the interesting thing is after this error guest fs have been thaw, i can use domfsfreeze to this guest again.
Hi Michal, I meet a issue during verify this bug(please see comment 4). Would you please help me to check out if it is a issue need fix in this bug? Or it is a another issue need open a new bug? Thanks in advance for your answer.
(In reply to Luyao Huang from comment #5) > Hi Michal, > > I meet a issue during verify this bug(please see comment 4). > > Would you please help me to check out if it is a issue need fix > in this bug? Or it is a another issue need open a new bug? > > Thanks in advance for your answer. Yep, that's a libvirt issue. I've proposed patch here: https://www.redhat.com/archives/libvir-list/2014-November/msg01043.html
Fixed upstream by: commit 6085d917d5c5839b7ed351e99fadbbb56f5178fe Author: Michal Privoznik <mprivozn@redhat.com> Date: Thu Nov 27 11:43:56 2014 +0100 qemu: Don't track quiesced state of FSs https://bugzilla.redhat.com/show_bug.cgi?id=1160084 As of b6d4dad11b (1.2.5) we are trying to keep the status of FSFreeze in the guest. Even though I've tried to fixed couple of corner cases (6ea54769ba18), it occurred to me just recently, that the approach is broken by design. Firstly, there are many other ways to talk to qemu-ga (even through libvirt) that filesystems can be thawed (e.g. qemu-agent-command) without libvirt noticing. Moreover, there are plenty of ways to thaw filesystems without even qemu-ga noticing (yes, qemu-ga keeps internal track of FSFreeze status). So, instead of keeping the track ourselves, or asking qemu-ga for stale state, it's the best to let qemu-ga deal with that (and possibly let guest kernel propagate an error). Moreover, there's one bug with the following approach, if fsfreeze command failed, we've executed fsthaw subsequently. So issuing domfsfreeze in virsh gave the following result: virsh # domfsfreeze gentoo Froze 1 filesystem(s) virsh # domfsfreeze gentoo error: Unable to freeze filesystems error: internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': The command guest-fsfreeze-freeze has been disabled for this instance virsh # domfsfreeze gentoo Froze 1 filesystem(s) virsh # domfsfreeze gentoo error: Unable to freeze filesystems error: internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': The command guest-fsfreeze-freeze has been disabled for this instance Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
I will change this bug to VERIFIED status after test with libvirt-1.2.8-10.el7.x86_64 After do domfsfreeze, then do save/managersave/migrate, it works as expected. Steps refer to comment 0 and comment 4
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHSA-2015-0323.html