System Management Guide:
Operating System and Devices

System Resource Controller and Subsystems

This section contains procedures for starting and stopping, tracing, and obtaining status of the System Resource Controller (SRC) subsystems, including:

• Starting the System Resource Controller
• Starting or Stopping a Subsystem, Subsystem Group, or Subserver
• Displaying the Status of a Subsystem or Subsystems
• Refreshing a Subsystem or Subsystem Group
• Turning On or Off Subsystem, Subsystem Group, or Subserver Tracing

Starting the System Resource Controller

The System Resource Controller (SRC) is started during system initialization with a record for the /usr/sbin/srcmstr daemon in the /etc/inittab file. The default /etc/inittab file already contains such a record, so this procedure might be unnecessary. You can also start the SRC from the command line, a profile, or a shell script, but there are several reasons for starting it during initialization:

• Starting the SRC from the /etc/inittab file allows the init command to restart the SRC if it stops for any reason.
• The SRC is designed to simplify and reduce the amount of operator intervention required to control subsystems. Starting the SRC from any source other than the /etc/inittab file is counterproductive to that goal.
• The default /etc/inittab file contains a record for starting the print scheduling subsystem (qdaemon) with the startsrc command. Typical installations have other subsystems started with startsrc commands in the /etc/inittab file as well. Because the srcmstr command requires the SRC be running, removing the srcmstr daemon from the /etc/inittab file causes these startsrc commands to fail.

See the srcmstr command for the configuration requirements to support remote SRC requests.

Prerequisites

• Reading and writing the /etc/inittab file requires root user authority.
• The mkitab command requires root user authority.
• The srcmstr daemon record must exist in the /etc/inittab file.

Procedure

1. Make a record for the srcmstr daemon in the /etc/inittab file using the mkitab command. For example, to make a record identical to the one that appears in the default /etc/inittab file, type:

   mkitab -i fbcheck srcmstr:2:respawn:/usr/sbin/srcmstr

   The -i fbcheck flag ensures that the record is inserted before all subsystems records.

2. Tell the init command to reprocess the /etc/inittab file by typing:

   telinit q

   When init revisits the /etc/inittab file, it processes the newly entered record for the srcmstr daemon and starts the SRC.

Starting or Stopping a Subsystem, Subsystem Group, or Subserver

Use the startsrc command to start a System Resource Controller (SRC) resource such as a subsystem, a group of subsystems, or a subserver. The startsrc command can be used:

• From the /etc/inittab file so the resource is started during system initialization
• From the command line
• With SMIT.

When you start a subsystem group, all of its subsystems are also started. When you start a subsystem, all of its subservers are also started. When you start a subserver, its parent subsystem is also started if it is not already running.

Use the stopsrc command to stop an SRC resource such as a subsystem, a group of subsystems, or a subserver. When you stop a subsystem, all its subservers are also stopped. However, when you stop a subserver, the state of its parent subsystem is not changed.

Both the startsrc and stopsrc commands contain flags that allow requests to be made on local or remote hosts.See the srcmstr command for the configuration requirements to support remote SRC requests.

Prerequisites

• To start or stop an SRC resource, the SRC must be running. The SRC is normally started during system initialization. The default /etc/inittab file, which determines what processes are started during initialization, contains a record for the srcmstr daemon (the SRC). To see if the SRC is running, type ps -A and look for a process named srcmstr.
• The user or process starting an SRC resource must have root user authority. The process that initializes the system (init command) has root user authority.
• The user or process stopping an SRC resource must have root user authority.

Displaying the Status of a Subsystem or Subsystems

Use the lssrc command to display the status of a System Resource Controller (SRC) resource such as a subsystem, a group of subsystems, or a subserver.

All subsystems can return a short status report that includes which group the subsystem belongs to, whether the subsystem is active, and what its process ID (PID) is. If a subsystem does not use the signals communication method, it can be programmed to return a long status report containing additional status information.

The lssrc command provides flags and parameters for specifying the subsystem by name or PID, for listing all subsystems, for requesting a short or long status report, and for requesting the status of SRC resources either locally or on remote hosts.

See the srcmstr command for the configuration requirements to support remote SRC requests.

Refreshing a Subsystem or Subsystem Group

Use the refresh command to tell a System Resource Controller (SRC) resource such as a subsystem or a group of subsystems to refresh itself.

The refresh command provides flags and parameters for specifying the subsystem by name or PID. You can also use it to request a subsystem or group of subsystems be refreshed, either locally or on remote hosts. See the srcmstr command for the configuration requirements to support remote SRC requests.

Prerequisites

• The SRC must be running. See Starting the System Resource Controller for details.
• The resource you want to refresh must not use the signals communications method.
• The resource you want to refresh must be programmed to respond to the refresh request.

Turning On or Off Subsystem, Subsystem Group, or Subserver Tracing

Use the traceson command to turn on tracing of a System Resource Controller (SRC) resource such as a subsystem, a group of subsystems, or a subserver.

Use the tracesoff command to turn off tracing of a System Resource Controller (SRC) resource such as a subsystem, a group of subsystems, or a subserver.

The traceson and traceoff commands can be used to remotely turn on or turn off tracing on a specific host. See the srcmstr command for the configuration requirements for supporting remote SRC requests.

Prerequisites

• To turn the tracing of an SRC resource either on or off , the SRC must be running. See Starting the System Resource Controller for details.
• The resource you want to trace must not use the signals communications method.
• The resource you want to trace must be programmed to respond to the trace request.