HP-UX SNAplus2 R7 Administration Guide

Appendix DUsing SNAplus2 in a High Availability Environment
Figure D–10 Accessing SNAplus2 Server via LAN
User
3xxx
Communications
Controller
IBM
Host
LAN
S800
Server
rlogin
Workstation
connection
D.3.6 Customizing the SNAplus2 Package Control Script
The last step in defining an SNAplus2 package is customizing the Package Control Script to instruct ServiceGuard
how to start and stop the SNAplus2 software associated with the package. The example file that we used in
our list of suggestions is /etc/cmcluster/sna/sna.cntl. See Table D–2, Suggestions for Defining the
SNAplus2 Package. To customize the Package Control Script, you must use an editor like vi. Package Control
Script customization cannot be done using SAM.
Modifying the PATH variable
Since the run and halt commands will use SNAplus2 executable programs, you must add the SNAplus2 executable
directory to the PATH variable in the Package Control Script. Add the directory /opt/sna/bin to the PATH
variable.
Adding Customer Defined Functions
To finish the SNAplus2 package definition, add commands to start and stop the SNAplus2 package to the Package
Control Script. The commands you will use depend on your specific SNA network configuration. If possible,
design the run and halt commands to migrate the SNAplus2 package to another server transparently; that is, without
impacting the applications. For the best level of application transparency, we recommend that you use a client/
server configuration, and that you configure ServiceGuard to activate the same SNAplus2 node, port, and LS on
the backup server that is configured to run on the primary server. This way, the SNAplus2 applications can access
the same set of LUs whether the SNA network connectivity is being provided by the primary server or the backup
server.
Note
We recommend that you use a client/server configuration in high availability environments.
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