Bug 1050835

Summary: [vdsm] [RO-disks] cannot create snapshot to VM with attached RO disk
Product: [Retired] oVirt Reporter: Elad <ebenahar>
Component: vdsmAssignee: Allon Mureinik <amureini>
Status: CLOSED DUPLICATE QA Contact: Aharon Canan <acanan>
Severity: high Docs Contact:
Priority: unspecified    
Version: 3.4CC: abaron, acathrow, bazulay, gklein, hateya, iheim, lpeer, mgoldboi, yeylon
Target Milestone: ---Keywords: Triaged
Target Release: 3.4.0   
Hardware: x86_64   
OS: Unspecified   
Whiteboard: storage
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-01-12 15:18:12 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: Storage RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
engine, vdsm, libvirt and qemu logs none

Description Elad 2014-01-09 08:00:53 UTC 
Created attachment 847520 [details]
engine, vdsm, libvirt and qemu logs

Description of problem:
Creation of snapshot to VM with read-only fails on VDSM with error message from libvirt

Version-Release number of selected component (if applicable):


How reproducible:
100%

Steps to Reproduce:
1. Create a VM and install OS
2. Attach a second RO disk and plug it to the VM
3. While VM is running and the 2 disks are active, try to create a snapshot

Actual results:

vmSnapshot call:

Thread-7898::DEBUG::2014-01-08 21:49:16,103::BindingXMLRPC::962::vds::(wrapper) client [10.35.163.52]::call vmSnapshot with ('476c7b76-706d-4799-9c3f-98c58f12fc03', [{'baseVolumeID': '106187b0-2644-4ef3-b0ac-6d04f28709ac', 'domainID': '8261440d-83ad-4d94-9d6b-1b75b74d3537', 'volumeID': 'c1834c28-e823-48c3-8d1c-d6e5f7ba97cd', 'imageID': 'a93fc335-914c-4ddf-bc87-4fc96335a55c'}], '8261440d-83ad-4d94-9d6b-1b75b74d3537,91be6d5c-bb17-497e-8fc9-0b7260057d48,4cfa44fc-fcf2-49ad-b492-c39c80d9eec7,3459e7b3-3044-4e89-85a0-9da9e60730e6,a20e9d7e-6ee2-45ce-9aa8-fcda838e3792,c00b4711-1955-4308-bb53-27187d8ab82c') {}



Snapshot creation fails with the following error in vdsm.log

Thread-7898::ERROR::2014-01-08 21:49:38,052::vm::3925::vm.Vm::(snapshot) vmId=`476c7b76-706d-4799-9c3f-98c58f12fc03`::Unable to take snapshot
Traceback (most recent call last):
  File "/usr/share/vdsm/vm.py", line 3923, in snapshot
    self._dom.snapshotCreateXML(snapxml, snapFlags)
  File "/usr/share/vdsm/vm.py", line 826, in f
    ret = attr(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/vdsm/libvirtconnection.py", line 92, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib64/python2.6/site-packages/libvirt.py", line 1636, in snapshotCreateXML
    if ret is None:raise libvirtError('virDomainSnapshotCreateXML() failed', dom=self)
libvirtError: Operation not supported: live disk snapshot not supported with this QEMU binary


Expected results:
AFAIK, RO disk shouldn't be part of the images table of the snapshot. That shouldn't fail the snapshot creation operation. 

Additional info:
engine, vdsm, libvirt and qemu logs
Comment 1 Elad 2014-01-09 08:03:09 UTC 
Version-Release number of selected component (if applicable):
vdsm-4.13.0-327.gitf4315ec.el6.x86_64
libvirt-0.10.2-29.el6_5.2.x86_64
qemu-kvm-0.12.1.2-2.415.el6_5.3.x86_64
ovirt-engine-3.4.0-0.2.master.20140106180914.el6.noarch
Comment 2 Allon Mureinik 2014-01-12 15:18:12 UTC 
You are using a qemu version that does not support live snapshots, regardless of r/o disks (see bug 1009100 for the details).

Please try to recreate the issue with a qemu version that does support it (qemu-kvm-rhev), and if the problem persists, reopen the bug.

*** This bug has been marked as a duplicate of bug 1009100 ***