Managing Serviceguard 14th Edition, June 2007

Understanding Serviceguard Software Components
Volume Managers for Data Storage
Chapter 3 117
Types of Volume Manager
Serviceguard allows a choice of volume managers for data storage:
• HP-UX Logical Volume Manager (LVM) and (optionally)
Mirrordisk/UX
• Veritas Volume Manager for HP-UX (VxVM)—Base and add-on
Products
• Veritas Cluster Volume Manager for HP-UX (CVM), if available (see
“About Veritas CFS and CVM from Symantec” on page 29)
Separate sections in Chapters 5 and 6 explain how to configure cluster
storage using all of these volume managers. The rest of the present
section explains some of the differences among these available volume
managers and offers suggestions about appropriate choices for your
cluster environment.
NOTE The HP-UX Logical Volume Manager is described in the HP-UX System
Administrator’s Guide. Release Notes for Veritas Volume Manager
contain a description of Veritas volume management products.
HP-UX Logical Volume Manager (LVM)
Logical Volume Manager (LVM) is the default storage management
product on HP-UX. Included with the operating system, LVM is available
on all cluster nodes. It supports the use of Mirrordisk/UX, which is an
add-on product that allows disk mirroring with up to two mirrors (for a
total of three copies of the data).
Currently, the HP-UX root disk can be configured as an LVM volume
group. (Note that, in this case, the HP-UX root disk is not the same as
the Veritas root disk group, rootdg, which must be configured in
addition to the HP-UX root disk on any node that uses Veritas Volume
Manager 3.5 products. The rootdg is no longer required with Veritas
Volume Manager 4.1 and later products.) The Serviceguard cluster lock
disk also is configured using a disk configured in an LVM volume group.
LVM continues to be supported on HP-UX single systems and on
Serviceguard clusters.