Administration Guide

Enabling and Disabling CS/AIX on the Local System

You must enable the CS/AIX software before you can use any CS/AIX tools (including the Motif administration program). Normally, the software is enabled automatically after you install CS/AIX, but if necessary you can enable it manually.

This section explains how to enable and disable the CS/AIX software.

Specifying the Path to CS/AIX Programs

CS/AIX executable programs are stored in a directory specific to CS/AIX; when you run the programs, you need to specify the path to this directory. You can specify the path either by adding the directory to your PATH environment variable before you run the programs for the first time, or by including the directory name each time you run the programs.

The Motif administration program is stored in the directory /usr/bin/X11, and the other programs are stored in the directory /usr/bin. If you add these directories to the definition of the PATH environment variable in your .login or .profile file, CS/AIX locates the programs automatically. Alternatively, you can specify the directory name when you run the program, as in the following examples:

/usr/bin/sna start

/usr/bin/snaadmin query_node

/usr/bin/X11/xsnaadmin

The sample command lines shown in this manual assume that you have added the directories to your PATH environment variable, and do not include the directory names.

Enabling CS/AIX Servers

You must enable CS/AIX on the local system before you can configure or manage the local node (either locally or from a remote CS/AIX node).

To enable the CS/AIX software, enter the following command at the AIX command prompt:
sna start [ -s ] [ -m kernel_memory_limit] [ -t ]

When you install CS/AIX, the installation utility automatically updates the startup file /etc/inittab to add an entry for /etc/rc.sna, which includes the sna start command. This ensures that CS/AIX is started automatically at system startup. If you do not want CS/AIX to be started automatically, you can remove or comment out this line, and then follow the instructions in this section to enable the CS/AIX software manually.

The parameters and options for the sna start command are as follows:

-s

Specifies that CS/AIX should not write messages to the system console. If you do not use this option, CS/AIX writes messages to the console when it ends, and also writes the text of certain error log messages to the console as well as to the log file.

-m kernel_memory_limit

Specifies the maximum amount of kernel memory, in kilobytes, that CS/AIX should use at any time. (Kernel memory is used for internal data structures.) If a component of CS/AIX attempts to allocate kernel memory that would cause the total amount of memory currently allocated to CS/AIX components to exceed this limit, the allocation attempt fails.

If you do not use this option, kernel memory usage is not limited.

-t

Activates tracing on all interfaces between kernel components. (This option does not turn on DLC tracing.) Tracing enables you to diagnose problems that occur during startup. If you do not use this option, tracing is inactive at all interfaces; you can then activate it on specific interfaces as required, using the command-line administration program snaadmin.

Tracing on all interfaces degrades the performance of CS/AIX components. After the software is enabled, you can use the command-line administration program snaadmin to stop tracing on any interfaces where it is not required. For more information about tracing, refer to Communications Server for AIX Diagnostics Guide.

CS/AIX writes messages to standard error (normally your terminal's screen) to indicate that it is initializing, and to indicate whether initialization completes successfully.

If initialization fails, the messages include information about the cause of the error, and (where appropriate) additional information such as the AIX operating system error message. The text written to standard error may also include a message indicating that you can find further information in the error log file. The sna start command then ends with a nonzero exit code that indicates the nature of the error.

For more information about exit code values, refer to Communications Server for AIX Diagnostics Guide.

Disabling CS/AIX Servers

Disabling the CS/AIX software automatically stops the CS/AIX node and its associated connectivity components. Disabling CS/AIX also stops any other processes (such as a 3270 emulation program) from using CS/AIX resources on this server.

In general, you should stop individual services as users finish using them, and only disable the system when there is no CS/AIX activity.

If you need to disable CS/AIX while users are active, warn users that CS/AIX is stopping, and give them time to finish their activities before you disable the software. Use the Motif administration program or the command-line administration program to view details of active users.

If a 3270 emulation program is using LUs on the node when you disable the CS/AIX software, all 3270 emulation sessions using these LUs end. The program continues to run, but the user cannot use the sessions until the software is re-enabled. Applications using the APPC, CSV, LUA, NOF, or MS APIs are notified by a COMM_SUBSYSTEM_ABENDED return code and CPI-C applications by a CM_PRODUCT_SPECIFIC_ERROR return code.

To disable the CS/AIX software, enter the following command at the AIX command prompt:
sna stop

If CS/AIX is disabled successfully, sna stop returns an exit code of 0. Any other exit code indicates that an error occurred and that the CS/AIX software was not disabled. Refer to Communications Server for AIX Diagnostics Guide for more information about exit code values.