srcmstr Daemon

Purpose

Starts the System Resource Controller.

Syntax

srcmstr /usr/sbin/srcmstr [ -r ] [ -B ]

Description

The srcmstr daemon is the System Resource Controller (SRC). The srcmstr daemon spawns and controls subsystems, handles short subsystem status requests, passes requests on to a subsystem, and handles error notification.

The srcmstr daemon is normally started by using an inittab file entry.

Flags

Item Description
-r Accepts remote requests if the daemon is started with the -r flag. If you start srcmstr without the -r flag, remote requests are ignored.
-B Specifies the -B flag that causes the srcmstr daemon to run as in previous releases (AIX® 4.3.1 and earlier).
Note:
  1. The srcmstr daemon is typically started from inittab. To add the -r or -B flags, edit /etc/inittab and run init q or reboot.
  2. The user must be running as root on the remote system. The local /etc/hosts.equiv file or the /.rhosts file must be configured to allow remote requests.

Security

Attention RBAC users and Trusted AIX users: This command can perform privileged operations. Only privileged users can run privileged operations. For more information about authorizations and privileges, see Privileged Command Database in AIX Version 7.1 Security. For a list of privileges and the authorizations associated with this command, see the lssecattr command or the getcmdattr subcommand.

Auditing Events: If the auditing subsystem has been properly configured and is enabled, the srcmstr command will generate the following audit record (event) every time the command is executed:

Event Information
SRC_Start Lists in an audit log the name of the subsystems being started.
SRC_Stop Lists in an audit log the name of the subsystems being stopped.

See Setting Up Auditing in AIX Version 7.1 Security for more details about how to properly select and group audit events, and how to configure audit event data collection.

Error Recovery

The default /etc/inittab specifies the respawn flag for the srcmstr daemon. If the srcmstr daemon terminates abnormally and the /etc/inittab specifies the respawn flag, the srcmstr daemon is restarted. It then determines which SRC subsystems were active during the previous invocation. The daemon re-establishes communication with these subsystems (if it existed previously), and initializes a private kernel extension and the srcd daemon to monitor the subsystem processes.

If a subsystem known to the previous invocation of srcmstr terminates, the SRC kernel extension notifies the srcd daemon. The srcd daemon sends a socket message to srcmstr and subsystem termination is handled as if the subsystem had been started by the current srcmstr. This function can be disabled by specifying the -B flag when the srcmstr daemon is started. The SRC kernel extension is in /usr/lib/drivers/SRC_kex.ext. The executable for srcd is /usr/sbin/srcd.

Files

Item Description
/etc/inittab Specifies stanzas read by the init command.
/etc/objrepos/SRCsubsys Specifies the SRC Subsystem Configuration Object Class.
/etc/objrepos/SRCnotify Specifies the SRC Notify Method Object Class.
/etc/hosts.equiv Specifies that no remote requests will work if the specified host name is not in the /etc/hosts.equiv file.
/etc/services Defines the sockets and protocols used for Internet services.
/dev/SRC Specifies the AF_UNIX socket file.
/dev/.SRC-unix Specifies the location for temporary socket files.
/dev/.SRC-unix/SRCD Specifies the AF_UNIX socket file for the srcd daemon.
/var/adm/SRC/active_list Contains a list of active subsystems.

Caution: The structure of this file is internal to SRC and is subject to change.
/var/adm/SRC/watch_list Contains a list of subsystem processes active during the previous invocation of the srcmstr daemon.

Caution: The structure of this file is internal to SRC and is subject to change.
/.rhosts Specifies remote machines and users (root only) that are allowed to request SRC function from this machine.