System Administration Guide: Basic Administration

Introduction to SMF

SMF provides an infrastructure that augments the traditional UNIX start-up scripts, init run levels, and configuration files. SMF provides the following functions:

Dependency statements define the relationships between services. These relationships can be used to provide precise fault containment by restarting only those services that are directly affected by a fault, rather than restarting all of the services. Another advantage of dependency statements is that the statements allow for scalable and reproducible initialization processes. In addition, by defining all of the dependencies, you can take advantage of modern, highly parallel machines, because all independent services can be started in parallel.

SMF defines a set of actions that can be invoked on a service by an administrator. These actions include enable, disable, refresh, restart, and maintain. Each service is managed by a service restarter which carries out the administrative actions. In general, the restarters carry out actions by executing methods for a service. Methods for each service are defined in the service configuration repository. These methods allow the restarter to move the service from one state to another state.

The service configuration repository provides a per-service snapshot at the time that each service is successfully started so that fallback is possible. In addition, the repository provides a consistent and persistent way to enable or disable a service, as well as a consistent view of service state. This capability helps you debug service configuration problems.