Managing HP Serviceguard for Linux, Tenth Edition, September 2012

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 Serviceguard Extended Distance Cluster (XDC) for Linux. 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 $SGCONF/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.
Configuring a Legacy Package 277