Managing HP Serviceguard for Linux Ninth Edition, April 2009

the previous node. This is accomplished by activating the volume group and mounting
the file system that resides on it.
In Serviceguard, high availability applications, services, and data are located in volume
groups that are on a shared bus. When a node fails, the volume groups containing the
applications, services, and data of the failed node are deactivated on the failed node
and activated on the adoptive node (the node the packages move to). In order for this
to happen, you must configure the volume groups so that they can be transferred from
the failed node to the adoptive node.
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 Volume Group Activation
Protection” (page 163) 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 0 0 # 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.
Package Configuration Planning 119