HP-UX System Administrator's Guide: Overview

NOTE: The pools of space are called volume groups in the Logical Volume Manager
and disk groups in the VERITAS Volume Manager.
Both volume managers can co-exist on a server. Each volume manager keeps track of
which disks it is controlling and any given physical disk can only be a controlled by
one volume manager at a time. The utility vxvmconvert can convert an LVM physical
volume to a VxVM disk if you want to migrate a disk from LVM to VxVM for greater
configuration flexibility.
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...
Storage on HP-UX 51