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Created attachment 815441 [details] logs Description of problem: when I create a snapshot type image from a running instance, I can see that libvirt domain is killed and restarted. I am not sure this is a correct behaviour. Version-Release number of selected component (if applicable): openstack-nova-compute-2013.2-0.25.rc1.el6ost.noarch How reproducible: 100% Steps to Reproduce: 1. configure cinder to work with gluster as backend 2. boot an instance from an image 3. create a snapshot from the instance Actual results: libvirt server is killed and restarted during the create snapshot Expected results: I don't think that libvirt server should be killed Additional info: logs [root@cougar07 ~(keystone_admin)]# virsh -r list Id Name State ---------------------------------------------------- 12 instance-00000036 running [root@cougar07 ~(keystone_admin)]# virsh -r list Id Name State ---------------------------------------------------- [root@cougar07 ~(keystone_admin)]# virsh -r list Id Name State ---------------------------------------------------- [root@cougar07 ~(keystone_admin)]# virsh -r list Id Name State ---------------------------------------------------- 13 instance-00000036 shut off [root@cougar07 ~(keystone_admin)]# virsh -r list Id Name State ---------------------------------------------------- 13 instance-00000036 running
This is a known behaviour of nova compute. Until openstack-nova-2013.2-4 (which I think will be puddled soon) nova will use the so called "cold snapshots" which require the instance to be stopped. Nova will save the state of the instance and stop this one to bring it back after the snapshot of the disk has been taken. That will also causes bug 1022596, which is understandable as there is no instance to connect to during the snapshot. The other type of snapshot which RHOS will be using after the mentioned packages are added to the repositories is live snapshots. These require a specific functionality in qemu and libvirt (which has been backported to the version we ship in RHEL 6.5). With live snaps the instance is never stopped and the vnc connection is never lost!
Xavier, I believe I'm reading that as the instance is stopped during the snapshot create, which really has nothing to do with the libvirt server which is not stopped. Is that right?
(In reply to Dave Allan from comment #2) > Xavier, I believe I'm reading that as the instance is stopped during the > snapshot create, which really has nothing to do with the libvirt > server which is not stopped. Is that right? Right Dave, only the instance is stopped when doing an snapshot. In libvirt words, the domain is saved and destroyed with managedsave to prevent writes during the snapshot process. That's why it disappears for a moment from the listed domains in virsh.