The sacadm command is the top level of the SAF. The sacadm command primarily is used to add and remove port monitors such as ttymon and listen. Other sacadm functions include listing the current status of port monitors and administering port monitor configuration scripts.
The Service Access Controller program (SAC) oversees all port monitors. A system automatically starts the SAC upon entering multiuser mode.
When the SAC program is invoked, it first looks for, and interprets, each system's configuration script. You can use the configuration script to customize the SAC program environment. This script is empty by default. The modifications made to the SAC environment are inherited by all the “children” of the SAC. This inherited environment might be modified by the children.
After the SAC program has interpreted the per-system configuration script, the SAC program reads its administrative file and starts the specified port monitors. For each port monitor, the SAC program runs a copy of itself, forking a child process. Each child process then interprets its per-port monitor configuration script, if such a script exists.
Any modifications to the environment specified in the per-port monitor configuration script affect the port monitor and will be inherited by all its children. Finally, the child process runs the port monitor program by using the command found in the SAC program administrative file.
The following steps summarize what happens when SAC is first started:
The SAC program is started by the SMF service, svc:/system/sac:default.
The SAC program reads /etc/saf/_sysconfig,
the per-system configuration script.
The SAC program reads /etc/saf/_sactab,
the SAC administrative file.
The SAC program forks a child process for each port monitor it starts.
Each port monitor reads /etc/saf/pmtag/_config,
the per-port monitor configuration script.