Bug 1014645

Summary: RHEV-M: VM migration fails from 3.3 host to 3.2 host - cannot open disk image file
Product: Red Hat Enterprise Linux 6 Reporter: Pavel Novotny <pnovotny>
Component: libvirtAssignee: Libvirt Maintainers <libvirt-maint>
Status: CLOSED NOTABUG QA Contact: Virtualization Bugs <virt-bugs>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 6.4CC: acathrow, jdenemar, pnovotny
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-10-03 08:21:49 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Attachments:
Description Flags
libvirtd.log from the source 3.3 host
none
libvirtd.log from the target 3.2 host
none
VDSM log from the source 3.3 host
none
VDSM log from the target 3.2 host none

Description Pavel Novotny 2013-10-02 13:19:13 UTC
Created attachment 806453 [details]
libvirtd.log from the source 3.3 host

Description of problem:
Using RHEV-M with two hosts (3.3 and 3.2), migration of a VM from 3.3 host to 3.2 host fails. Libvirt throws an exception that it cannot find the VM disk image file, despite it's present on the filesystem.
Note: SELinux was set to permissive mode on both hosts.

Version-Release number of selected component (if applicable):
3.3 host:
libvirt-0.10.2-27.el6.x86_64
qemu-kvm-rhev-0.12.1.2-2.355.el6_4.7.x86_64
vdsm-4.12.0-156.git6e499d6.el6ev.x86_64

3.2 host:
libvirt-0.10.2-18.el6_4.14.x86_64
qemu-kvm-rhev-0.12.1.2-2.355.el6_4.2.x86_64
vdsm-4.10.2-25.1.el6ev.x86_64


How reproducible:
100%

Steps to Reproduce:
1. In RHEV-M, have 3.3 and 3.2 host in a 3.2 cluster.
2. Create new VM with a bootable disk and run it on the 3.3 host.
3. Migrate the VM to the 3.2 host.

Actual results:
Migration fails.
Error in libvirt log (attached): "virNetClientProgramDispatchError:174 : cannot open file '/var/run/vdsm/storage/84f6d841-6c6a-49be-a0f5-b7d80f876573/1985711b-46fd-4cb7-909b-1168f60b5547/548c7b86-b75e-441e-97b9-c163ffdacaca': No such file or directory".

Expected results:
Migration completes successfully.

Additional info:

The file in /var/run/vdsm/storage/ actually exists:
# ls -lh /var/run/vdsm/storage/84f6d841-6c6a-49be-a0f5-b7d80f876573/1985711b-46fd-4cb7-909b-1168f60b5547/548c7b86-b75e-441e-97b9-c163ffdacaca
-rw-rw----. 1 vdsm kvm 1,0G  2. říj 13.41 /var/run/vdsm/storage/84f6d841-6c6a-49be-a0f5-b7d80f876573/1985711b-46fd-4cb7-909b-1168f60b5547/548c7b86-b75e-441e-97b9-c163ffdacaca

Libvirt log file from the source 3.3 host attached (libvirt log on target host is empty).

Comment 2 Jiri Denemark 2013-10-02 14:29:35 UTC
The error is coming from the destination host and we need libvirtd logs from there. If the logs there are empty, I think there are some configuration issues on that host. Also where did you run the "ls -lh" command? On the source or destination host?

Comment 3 Pavel Novotny 2013-10-02 15:23:49 UTC
(In reply to Jiri Denemark from comment #2)
> The error is coming from the destination host and we need libvirtd logs from
> there. If the logs there are empty, I think there are some configuration
> issues on that host. ...

Ok, after a little bit of investigation I found the libvirt log on the target host, it was just at slightly different location then on the source host :) Put in attachment.

> Also where did you run the "ls -lh" command? On the
> source or destination host?

I ran the `ls` command on the source host.
On the destination host there was even no directory `/var/run/vdsm/storage/` when I checked after the failed migration (but it could have been already removed by VDSM). Attaching also the VDSM logs from both hosts.

Comment 4 Pavel Novotny 2013-10-02 15:25:20 UTC
Created attachment 806534 [details]
libvirtd.log from the target 3.2 host

Comment 5 Pavel Novotny 2013-10-02 15:26:22 UTC
Created attachment 806535 [details]
VDSM log from the source 3.3 host

Comment 6 Pavel Novotny 2013-10-02 15:27:11 UTC
Created attachment 806536 [details]
VDSM log from the target 3.2 host

Comment 7 Jiri Denemark 2013-10-03 08:21:49 UTC
Please, could you do a little bit more investigation before filing a bug next time, esp. if the error message is so clear? It may always be a bug but it's much better to check obvious thing before creating a bug report. I have no idea why the /var/run/vdsm/storage directory is not present on your 3.2 host but that's also part of the investigation since the most obvious reason is a bad configuration of vdsm on that host.

In any case, I'm closing this bug. Feel free to file a new one if you find a real bug there.