nova live snapshot of rbd instance fails on xen hypervisor
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
OpenStack Compute (nova) |
Expired
|
Undecided
|
Unassigned |
Bug Description
Description:
We use a Mitaka environment with one control and three compute nodes (all running on openSUSE Leap 42.1), the compute nodes are xen hypervisors, our storage backend is ceph (for nova, glance and cinder).
When we try to snapshot a running instance, it's always a cold snapshot, nova-compute reports:
2017-01-12 12:55:51.919 [instance: 14b75237-
2017-01-12 12:59:27.085 [instance: 14b75237-
On rbd level the live snapshot process works as expected, without any downtime of the instance, we use it for our backup strategy for example.
With some additional log statements in /usr/lib/
---cut here---
compute1:~ # diff -u /usr/lib/
--- /usr/lib/
+++ /usr/lib/
@@ -1649,9 +1649,14 @@
# redundant because LVM supports only cold snapshots.
# It is necessary in case this situation changes in the
# future.
+ if CONF.libvirt.
+ hv_driver = host.HV_DRIVER_XEN
+ else:
+ hv_driver = host.HV_DRIVER_QEMU
+
if (self._
- host.HV_
+ hv_driver)
and source_type not in ('lvm')
and not CONF.ephemeral_
and not CONF.workaround
---cut here---
nova-compute reports:
2017-01-12 17:20:22.760 [instance: 14b75237-
2017-01-12 17:20:24.049 [instance: 14b75237-
2017-01-12 17:24:38.997 [instance: 14b75237-
The versions we use:
compute1:~ # nova --version
3.3.0
compute1:~ # ceph --version
ceph version 0.94.7-84-g8e6f430 (8e6f430683e4d8
compute1:~ # libvirtd --version
libvirtd (libvirt) 2.5.0
compute1:~ # qemu-img --version
qemu-img version 2.7.0((SUSE Linux)), Copyright (c) 2003-2016 Fabrice Bellard and the QEMU Project developers
compute1:~ # rpm -qa | grep xen
xen-4.7.
What is the value of the "virt_type" config option in nova.conf on the compute? That defaults to 'kvm' for the libvirt driver, but if you're using xen with the libvirt driver then virt_type=xen in nova.conf in the [libvirt] group.