Managing HP Serviceguard A.11.20.10 for Linux, December 2012

4.8 Package Configuration Planning
Planning for packages involves assembling information about each group of highly available
services.
NOTE: As of Serviceguard A.11.18, there is a new and simpler way to configure packages.
This method allows you to build packages from smaller modules, and eliminates the separate
package control script and the need to distribute it manually; see Chapter 6: “Configuring Packages
and Their Services ” (page 163), for complete instructions.
This manual refers to packages created by the newer method as modular packages, and to packages
created by the older method as legacy packages.
The discussion that follows assumes you will be using the modular method. For information and
instructions on creating and maintaining legacy packages, see “Configuring a Legacy Package”
(page 225).
The document HP Serviceguard Developer’s Toolbox User Guide, December 2012 provides a
guide for integrating an application with Serviceguard using a suite of customizable scripts known
as "Serviceguard Developer’s Toolbox" intended for use with modular packages only. The
“Serviceguard Developer’s Toolbox” is available free of charge and can be downloaded from
Software Depot at http://h20392.www2.hp.com/portal/swdepot/displayProductInfo.do?
productNumber=SGDTOOLBOX.
NOTE: The HP Serviceguard Developer’s Toolbox User Guide, December 2012 deals specifically
with modular packages only. The Serviceguard Developer’s Toolbox do not support legacy style
packages.
4.8.1 Logical Volume and File System Planning
Use logical volumes in volume groups as the storage infrastructure for package operations on a
cluster. When the package moves from one node to another, it must still be able to access the
same data on the same disk as it did when it was running 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 (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 142)
for instructions. However, if you are using PR feature this step is not required.
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.
100 Planning and Documenting an HA Cluster