VERITAS Volume Manager 3.5 Administrator's Guide (September 2004)

Understanding VERITAS Volume Manager
How VxVM Handles Storage Management
Chapter 14
How VxVM Handles Storage Management
VxVM uses two types of objects to handle storage management: physical
objects and virtual objects.
• Physical objects—Physical disks or other hardware with block and
raw operating system device interfaces that are used to store data.
• Virtual objects—When one or more physical disks are brought under
the control of VxVM, it creates virtual objects called volumes on
those physical disks. Each volume records and retrieves data from
one or more physical disks. Volumes are accessed by file systems,
databases, or other applications in the same way that physical disks
are accessed. Volumes are also composed of other virtual objects
(plexes and subdisks) that are used in changing the volume
configuration. Volumes and their virtual components are called
virtual objects or VxVM objects.
Physical Objects—Physical Disks
A physical disk is the basic storage device (media) where the data is
ultimately stored. You can access the data on a physical disk by using a
device name to locate the disk. The physical disk device name varies with
the computer system you use. Not all parameters are used on all
systems. Typical device names are of the form c#t#d# [s2], where:
• c# specifies the controller
• t# specifies the target ID
• d# specifies the disk
• s2 specifies a partition (only for EFI formatted disks used to boot HP
Itanium 2 based systems)