When a dynamic disk group is imported, the system
stamps its host ID on all disks in the dynamic disk group. A dynamic
disk group import fails if one of the disks is stamped with a host
ID that does not match the others. This ensures that dual-ported
disks cannot be managed (and possibly corrupted) by two systems
at the same time. If you are sure that the dynamic disk group is
not in use by another host, you can clear the host IDs and import
the dynamic disk group by selecting the Clear Host ID option.