[CentOS] QEMU configuration not persistent

[Emmett Culley]

On 02/13/2012 03:49 PM, Paul Heinlein wrote:
> On Mon, 13 Feb 2012, Emmett Culley wrote:
> 
>> Since switching from CentOS 5.7 to CentOS 6.x I find that one of the
>> VMs will not restart upon system reboot.  I finally figured out that
>> the video is always set to vmvga after rebooting.  In addition the
>> VM's storage always reverts back to IDE from virtio and is set to
>> use the wrong image.
>>
>> It may be related to the fact that I moved the XML files that
>> defined the VMs from the old (CentOS 5.7) /etc/libvirt/qemu
>> directory to the new (CentOS 6.2) /etc/libvirt/qemu directory.  The
>> images are stored is the same LVM partitions as they were on the
>> CentOS 5.7
>>
>> Any ideas why a VM would revert back?  I've checked the XML file
>> before rebooting and it always has the correct info in it, until
>> after the reboot.
> 
> Did you copy the XML file from the 5.7 host to 6.3 host as-is or did
> you edit it at all during the migration?
> 
> I've found that I need either to run "virsh define $DOM.xml" and then
> start the new domain or run "virsh create $DOM.xml" and then, once
> it's running, make a trivial change (usually adding an XML comment) to
> the configuration via "virsh edit $DOM" to get things to stick.
> 
I did copy the XML files to the 6.2 machine.  Then when I found that the VMs would not start because they were set to vmvga video, which doesn't seem to be supported anymore, I changed the XML files to cirrus.

Then I tried editing the VM using virsh, but still it doesn't persist.  

Hmm. There is only one of the VMs that doesn't persist so I'll try using virsh edit again on that one and make a change as you suggest, just in case I never really changed anything for that VM using virsh edit.

Thanks,
  Emmett