Outside the context of CVM, VxVM disk groups can be imported (made available) on only one host at any given time. When a host imports a (private) disk group, the volumes and configuration of that disk group become accessible to the host. If the administrator or system software wants to privately use the same disk group from another host, the host that already has the disk group imported (importing host) must deport (give up access to) the disk group. Once deported, the disk group can be imported by another host.
If two hosts are allowed to access a disk group concurrently without proper synchronization, such as that provided by Oracle RAC, the configuration of the disk group, and possibly the contents of volumes, can be corrupted. Similar corruption can also occur if a file system or database on a raw disk partition is accessed concurrently by two hosts, so this problem in not limited to Veritas Volume Manager.