Migration Does Not Fail If a vdsdev on the Target Has a Different Backend

Bug ID 6772120: If the virtual disk on the target machine does not point to the same disk backend that is used on the source machine, the migrated domain cannot access the virtual disk using that disk backend. A hang can result when accessing the virtual disk on the domain.

Currently, the Logical Domains Manager checks only that the virtual disk volume names match on the source and target machines. In this scenario, no error message is displayed if the disk backends do not match.

Workaround: Ensure that when you are configuring the target domain to receive a migrated domain that the disk volume (vdsdev) matches the disk backend used on the source domain.

Recovery: Do one of the following if you discover that the virtual disk device on the target machine points to the incorrect disk backend:

• Do the following:

  • Migrate the domain back to the source machine.

  • Fix the vdsdev on the target to point to the correct disk backend.

  • Migrate the domain to the target machine again.

• Stop and unbind the domain on the target, and fix the vdsdev. If the OS supports virtual I/O dynamic reconfiguration, and the incorrect virtual disk in not in use on the domain (that is, it is not the boot disk and is unmounted), do the following:

  • Use the ldm rm-vdisk command to remove the disk.

  • Fix the vdsdev.

  • Use the ldm add-vdisk command to add the virtual disk again.