A VxVM virtual device is defined by a volume. A volume has a layout defined by the association of a volume to one or more plexes, each of which map to one or more subdisks. The volume presents a virtual device interface that is exposed to other applications for data access. These logical building blocks re-map the volume address space through which I/O is re-directed at run-time.
Different volume layouts provide different levels of availability and performance. A volume layout can be configured and changed to provide the desired level of service.