Current read-write owner (instance ID).
May refer to an instance in any state, including stopped
(this semantics is preserved for backward compatibility).
Reassigned on disk detach, instance deletion, or ownership transfer.
Ownership transfer occurs when this disk is explicitly attached to another instance
or when a VM with this disk attached starts while the current owner is stopped.
Current read-write owner (instance ID). May refer to an instance in any state, including stopped (this semantics is preserved for backward compatibility). Reassigned on disk detach, instance deletion, or ownership transfer. Ownership transfer occurs when this disk is explicitly attached to another instance or when a VM with this disk attached starts while the current owner is stopped.