Managing HP Serviceguard for Linux, Seventh Edition, July 2007

Planning and Documenting an HA Cluster
Package Configuration Planning
Chapter 4114
NOTE To prevent an operator from accidentally activating volume groups on
other nodes in the cluster, versions A.11.16.07 and later of Serviceguard
for Linux include a type of VG activation protection. This is based on the
“hosttags” feature of LVM2.
This feature is not mandatory, but HP strongly recommends you
implement it as you upgrade existing clusters and create new ones. See
“Enabling VG Activation Protection” on page 168 for instructions.
As part of planning, you need to decide the following:
• What volume groups are needed?
• How much disk space is required, and how should this be allocated in
logical volumes?
• What file systems need to be mounted for each package?
• Which nodes need to import which logical volume configurations.
• If a package moves to an adoptive node, what effect will its presence
have on performance?
Create a list by package of volume groups, logical volumes, and file
systems. Indicate which nodes need to have access to common file
systems at different times.
HP recommends that you use customized logical volume names that are
different from the default logical volume names (lvol1, lvol2, etc.).
Choosing logical volume names that represent the high availability
applications that they are associated with (for example, lvoldatabase)
will simplify cluster administration.
To further document your package-related volume groups, logical
volumes, and file systems on each node, you can add commented lines to
the /etc/fstab file. The following is an example for a database
application:
# /dev/vg01/lvoldb1 /applic1 ext2 defaults 0 1 # These six entries are
# /dev/vg01/lvoldb2 /applic2 ext2 defaults 0 1 # for information purposes
# /dev/vg01/lvoldb3 raw_tables ignore ignore 00#only. They record the
# /dev/vg01/lvoldb4 /general ext2 defaults 0 2 # logical volumes that
# /dev/vg01/lvoldb5 raw_free ignore ignore 0 0 # exist for Serviceguard's
# /dev/vg01/lvoldb6 raw_free ignore ignore 0 0 # HA package. Do not uncomment.