Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a System: Managing Disks and Files
Managing Disks
Chapter 6558
The Logical Volume Manager (LVM)
Useful Facts About LVM
• To use LVM, a disk must be first initialized into a physical volume
(also called an LVM disk).
• Once you have initialized one or more physical volumes, you assign
them into one or more volume groups. If you think of all of your
physical volumes as forming a storage pool, then a subset of disks
from the pool can be joined together into a volume group.
• A given disk can only belong to one volume group. The maximum
number of volume groups that can be created is determined by the
configurable parameter maxvgs . See “Reconfiguring the Kernel (Prior
to HP-UX 11i Version 2)” on page 282 for information on modifying
system parameters.
• A volume group can contain from one to 255 physical volumes.
• Disk space from the volume group is allocated into a logical
volume, a distinct unit of usable disk space. A volume group can
contain up to 255 logical volumes.
• A logical volume can exist on only one disk or can reside on portions
of many disks.
• The disk space within a logical volume can be used for swap, dump,
raw data, or you can create a file system on it.