Managing Serviceguard Nineteenth Edition, Reprinted June 2011

Adding Serviceguard Commands in Customer Defined Functions
You can add Serviceguard commands (such as cmmodpkg) in the Customer Defined Functions
section of a package control script. These commands must not interact with the package itself.
If a Serviceguard command interacts with another package, be careful to avoid command loops.
For instance, a command loop might occur under the following circumstances. Suppose pkg1 does
a cmmodpkg -d of pkg2, and pkg2 does a cmmodpkg -d of pkg1. If both pkg1 and pkg2
start at the same time, pkg1 tries to cmmodpkg pkg2. However, that cmmodpkg command has
to wait for pkg2 startup to complete. pkg2 tries to cmmodpkg pkg1, but pkg2 has to wait for
pkg1 startup to complete, thereby causing a command loop.
To avoid this situation, it is a good idea to always specify a RUN_SCRIPT_TIMEOUT and a
HALT_SCRIPT_TIMEOUT for all packages, especially packages that use Serviceguard commands
in their control scripts. If a timeout is not specified and your configuration has a command loop
as described above, inconsistent results can occur, including a hung cluster.
Support for Additional Products
The package control script template provides exits for use with additional products, including
Metrocluster with Continuous Access/XP and EVA, Metrocluster with EMC SRDF, and the HA NFS
toolkit. Refer to the additional product’s documentation for details about how to create a package
using the hooks that are provided in the control script.
Verifying the Package Configuration
Serviceguard checks the configuration you create and reports any errors.
For legacy packages, you can do this in Serviceguard Manager: click Check to verify the package
configuration you have done under any package configuration tab, or to check changes you have
made to the control script. Click Apply to verify the package as a whole. See the local Help for
more details.
If you are using the command line, use the following command to verify the content of the package
configuration you have created:
cmcheckconf -v -P /etc/cmcluster/pkg1/pkg1.conf
Errors are displayed on the standard output. If necessary, edit the file to correct any errors, then
run the command again until it completes without errors.
The following items are checked (whether you use Serviceguard Manager or cmcheckconf
command):
• Package name is valid, and at least one NODE_NAME entry is included.
• There are no duplicate parameter entries.
• Values for parameters are within permitted ranges.
• Run and halt scripts exist on all nodes in the cluster and are executable.
• Run and halt script timeouts are less than 4294 seconds.
• Configured resources are available on cluster nodes.
• If a dependency is configured, the dependency package must already be configured in the
cluster.
Distributing the Configuration
You can use Serviceguard Manager or HP-UX commands to distribute the binary cluster configuration
file among the nodes of the cluster.
DSAU (Distributed Systems Administration Utilities) can help you streamline your distribution; see
“What are the Distributed Systems Administration Utilities?” (page 24).
294 Cluster and Package Maintenance