[Pkg-libvirt-maintainers] Bug#586217: Bug#586217: live migration corrupts virtio block device on NFSv4

[Harald Dunkel]

Hi Guido,

On 06/25/10 19:10, Guido Günther wrote:
> Hi Harald,
> On Mon, Jun 21, 2010 at 11:49:09AM +0200, Harald Dunkel wrote:
>> Do you think you could try to reproduce this.
> Seems so. I've checked two of for combinations so far:
>
>                 | --live | no --live |
> ---------------------------------------
> NFS-C ->  NFS-S |   ?    |  works    |
> NFS-S ->  NFS-C | fails  |    ?      |
>
> (NFS-S: NFS-Server, NFS-C: NFS-Client. The NFS server accesses the
> images as a local fs (ext3)). The ?-cases are unchecked.
>

Sorry, my NFS server is not permitted to run kvm and libvirt.
I got the problem for migrating live from one NFS client
to another.

If I omit the "--live"

	virsh migrate migtest qemu+ssh://fw02/system

then I get these I/O errors for the guest on the new host,
too.

> The image ends up as root:root instead of libvirt-qemu:kvm which could
> be the problem.

I got the "root:root", too.

> Next thing would be to check if setting
>
> 	user = root
> 	group = root
>
> in /etc/libvirt/qemu.conf changes anything.

If I set user and group to "root" on both NFS clients,
then the migration seems to work.

Actually NFSv4 is supposed to hide these details, but
libvirt-qemu:kvm is 200:200 on all my hosts.


Hope this helps. Regards

Harri