Managing HP Serviceguard for Linux, Sixth Edition, August 2006

Planning and Documenting an HA Cluster
Package Configuration Planning
Chapter 4 107
Package Configuration Planning
Planning for packages involves assembling information about each group
of highly available services. Some of this information is used in creating
the package configuration file, and some is used for editing the package
control script.
NOTE Volume groups that are to be activated by packages must also be defined
as cluster aware in the cluster configuration file. See the previous section
on “Cluster Configuration Planning.”
Logical Volume and File System Planning
You may need to use logical volumes in volume groups as part of the
infrastructure for package operations on a cluster. When the package
moves from one node to another, it must be able to access data residing
on the same disk as on 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. In order to do this, you have to 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 and so is not available on RedHat 3. This
feature is not mandatory, but HP strongly recommends you implement it
as you upgrade existing clusters and create new ones.
As part of planning, you need to decide the following: