the instance boot-from-volume evacuate failed

[Ding Xiao]

I tested the "nova evacuate" command and found a problem.
My operation steps are as below:
1.I created a volume on Cinder while cinder using lvm driver, and then launched a instance from the volume on host A.
2.When host A is broken down(or the compute service down), I use "nova evacuate instanceid-xxx new-host-name-B" command to resume the instance.
3.The instance launched failed on host B.I checked the libvirt xml, and found the diffrence as below:
the instance xml on A:

   <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none'/>
      <source dev='/dev/disk/by-path/ip-186.100.8.144:3260-iscsi-iqn.2010-10.org.openstack:volume-458e9b32-7f65-41ea-823f-9cffcfe4f2b8-lun-1'/>
      <target dev='vda' bus='virtio'/>
      <serial>458e9b32-7f65-41ea-823f-9cffcfe4f2b8</serial>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>

the instance xml on B:

   <disk type="file" device="disk">
      <driver name="qemu" type="qcow2" cache="none"/>
      <source file="/var/lib/nova/instances/b059ed87-6029-45c2-a36c-c7d48f64ad61/disk"/>
      <target bus="virtio" dev="vda"/>
    </disk>

[Ilja Livenson (ilja-t)]

The flow is broken also when using a 3par SAN over FC.

[Tushar Patil (tpatil)]

When I try to evacuate instance booted from volume I am getting below error on compute node:

http://paste.openstack.org/show/281945

Cinder volume driver: lvm driver

Note: Instance booted from image is getting evacuated successfully.

[Hidekazu Nakamura (nakamura-h)]

Instance booted from volume is evacuated successfully in my environment.

My environment:
 Release: Kilo
 Cinder volume driver: LVM driver