9.3. Logical Volume Manager Concepts
Since HP-UX 9.0, Logical Volume Manager (LVM) has become the most common tool for creating and managing disk storage. LVM provides the capability to group multiple physical disks into a single volume group composed of one or more logical volumes. Logical volumes can contain file systems, or they can be accessed like raw files.
Although non-default naming is possible, LVM objects usually have device file names beginning with /dev/vg (for example, /dev/vg00 for a volume group, and /dev/vg03/lvol9 for a logical volume). These objects are accessed via the LVM pseudo-driver, which in turn accesses either the block or character-mode driver to perform actual I/O to the disk.
Volume groups offer a great deal more ...