“boot failed: not a bootable disk” after migrating kvm image

i’ve migrated some vm from qemu-kvm-0.12.4 to qemu-kvm-0.12.5 and … got unpleasant surprise – unbootable machine.

full error message:

Booting from Hard Disk...
Boot failed: not a bootable disk

No bootable device.

solution [found here] was to change libvirt’s xml config from:

...
 <disk type='file' device='disk'>
   <driver name='qemu' />
   <source file='/mnt/vm/sda.qcow2' type='qcow2'/>

to

...
 <disk type='file' device='disk'>
   <driver name='qemu' type='qcow2'/>
   <source file='/mnt/vm/sda.qcow2' type='qcow2'/>