HP-UX System Administrator's Guide: Overview HP-UX 11i v3 (B3921-90011, September 2010)

Selecting a Volume Manager
With HP-UX 11i version 3, there are two volume managers to choose from:
• The HP Logical Volume Manager (LVM)
• The VERITAS Volume Manager (VxVM)
You can use both simultaneously (on different physical disks), but usually you will choose one
or the other and use it exclusively. Table 3-1 provides a comparison of the two volume managers
to help you determine which will best suit your needs.
Table 3-1 Volume Manager Feature and Terminology Comparison
VERITAS Volume Manager (VxVM)HP Logical Volume Manager (LVM)Feature
Check HP-UX 11i version 3 Release Notes
to see if VERITAS Volume Manager is
included with your chosen Operating
Environment
LVM is included in the HP-UX 11i
version 3 Foundation Operating
Environment
Obtaining...
VERITAS Volume Manager DisksPhysical VolumesPhysical Disks are called...
Disk GroupsVolume GroupsGroups of Physical Disks are called...
VolumesLogical VolumesLogical Storage Containers allocated
from the Volume/Disk Groups are
called...
Subdisks (arbitrary in size, subdisks
represent a set of disk blocks, allocated
from VERITAS Volume Manager Disks
in a disk group)
Physical Extents (fixed size chunks
of disk space, the size of which must
be the same for all physical volumes
in a given volume group)
User data within (Logical) Volumes
is allocated using...
a special area known as a “private
region” of each physical volume.
a special reserved area at the
beginning of each physical volume.
Volume and Volume Group
configuration information is stored
in...
Mirrors consist of plexes, each of which
is a copy of the volume being mirrored.
The base version of the VERITAS Volume
Manager allows you to mirror your root
file system (only).
Like LVM, VERITAS Volume Manager
requires an additional license to support
mirroring (beyond the mirroring of your
root file system), but with the additional
license VxVM supports up to 32 copies
of your data.
You need to add the MirrorDisk/UX
product to your system to support
mirroring. Mirrordisk/UX supports
up to three copies of data if you are
using LVM with Version 1 volume
groups, and up to six copies of data
if you are using LVM with Version
2 volume groups.
Mirrors (copies of data)
Storage on HP-UX 45