HP XC System Software Installation Guide Version 3.1

happens, the availability tool uses the IP alias to start the service on the second server in the availability
set. Client nodes do not detect that the first server has gone down.
1.9.2 How to Configure Improved Availability
Table 1-1 provides a summary of how to set up and configure improved availability of services. Detailed
information or procedures are provided at the appropriate points in the system installation and configuration
process, as noted in the second column of the table.
Table 1-1 Improved Availability Summary
Appropriate Task Details
Are Provided HereTask
“Choose an Availability
Tool” (page 27)
1. Decide which availability tool or tools you want to use; this tool manages the services for which
improved availability has been configured. Then, obtain or purchase, install, and configure the
availability tool or tools.
“Write Translator and
Other Supporting Scripts”
(page 28)
2. Write translator and supporting scripts for the availability tool if you are not using Serviceguard.
Then, position the translator and related scripts in the
/opt/hptc/availability/availability_tool directory.
“Choose Nodes as
Members of Availability
Sets” (page 28)
3. Decide which nodes you want to configure into availability sets.
“Role Assignments for
Improved Availability”
(page 28)
4. Determine the services for which you want to configure improved availability.
“Deciding on the Method
to Achieve Quorum for
Serviceguard Clusters”
(page 41)
5. If you are using Serviceguard as the availability tool, decide whether to use a quorum server or a
lock LUN to achieve quorum. You must create the lock LUN before running the cluster_config
utility.
“Task 8: Configure
Availability Sets” (page 66)
6. Invoke the cluster_config utility to configure the HP XC system. You are prompted to associate
nodes into availability sets.
“Task 9: Assign Node
Roles” (page 68)
7. Use the [M]odify Nodes option of the cluster_config utility to assign the appropriate roles
(and thus, the appropriate services) to the nodes in the availability sets. Both nodes in the availability
set must be assigned with the same roles.
“Task 14: Start Availability
Tools” (page 83)
8. Start the availability tool with the transfer_to_avail command when cluster_config
processing is complete and the HP XC system is booted.
1.9.3 Choose an Availability Tool
The first step in planning your service availability strategy is to decide on the availability tool or tools you
want to use to manage services that have been configured with improved availability. Many different
availability tools are on the market, and they all provide the same basic functionality. The availability
infrastructure of the HP XC System Software enables you to install more than one availability tool.
Regardless of the tool you choose, you install the availability tool software on the HP XC system after you
install the HP XC System Software on the head node. This document is designed sequentially, and you
are instructed to install the availability tool software at the appropriate time (“Task 4: Install Additional
Software from Local Distribution Media” (page 40)).
HP Serviceguard
In this release, HP Serviceguard is the recommended availability tool. Serviceguard enables system services
to continue if a hardware or software failure occurs. You must purchase and license Serviceguard separately
from the HP XC System Software product.
After purchasing Serviceguard, you install it from the Serviceguard distribution media. This document
instructs you to install a specific HP XC Serviceguard RPM® from the HP XC System Software distribution
DVD. This RPM enables Serviceguard to operate on an HP XC system.
HP Serviceguard 27