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AIX Version 4.3 System Management Guide: Operating System and Devices

System Resource Controller Overview

The System Resource Controller (SRC) provides a set of commands and subroutines to make it easier for the system manager and programmer to create and control subsystems. A subsystem is any program or process or set of programs or processes that is usually capable of operating independently or with a controlling system. A subsystem is designed as a unit to provide a designated function.

The SRC was designed to minimize the need for operator intervention. It provides a mechanism to control subsystem processes using a common command line and the C interface. This mechanism includes the following:

The SRC is useful if you want a common way to start, stop, and collect status information on processes.

Subsystem Components

A subsystem can have one or more of the following properties:

A few subsystem examples are ypserv, ntsd, qdaemon, inetd, syslogd, and sendmail.

Note: Refer to each specific subsystem for details of its SRC capabilities.

Use the lssrc -a command to list active and inactive subsystems on your system.

Subsystem Group

A subsystem group is a group of any specified subsystems. Grouping subsystems together allows the control of several subsystems at one time. A few subsystem group examples are TCP/IP, SNA Services, Network Information System (NIS), and Network File Systems (NFS).


A subserver is a program or process that belongs to a subsystem. A subsystem can have multiple subservers and is responsible for starting, stopping, and providing status of subservers. Subservers can be defined only for a subsystem with a communication type of IPC message queues and sockets. Subsystems using signal communications do not support subservers.

Subservers are started when their parent subsystems are started. If you try to start a subserver and its parent subsystem is not active, the startsrc command starts the subsystem as well.

SRC Hierarchy

The System Resource Controller has a hierarchical structure (see figure). The hierarchy begins with the operating system followed by a subsystem group (such as tcpip), which contains a subsystem (such as the inetd daemon), which in turn can own several subservers (such as the ftp daemon and the finger command).

List of SRC Administration Commands

srcmstr daemon
                          Starts the System Resource Controller.
startsrc command
                          Starts a subsystem, subsystem group, or subserver.
stopsrc command
                          Stops a subsystem, subsystem group, or subserver.
refresh command
                          Refreshes a subsystem.
traceson command
                          Turns on tracing of a subsystem, a group of subsystems, or a subserver.
tracesoff command
                          Turns off tracing of a subsystem, a group of subsystems, or a subserver.
lssrc command
                          Gets status on a subsystem.

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