Chapter 5: System Run Levels

In this chapter, you will

• Learn how to start up a Solaris system

• Learn how to shut down a Solaris system

• Discover the role of run levels/init states

• Review the role of the init command

• Learn how to write startup scripts

Solaris 9 uses a flexible boot process that is based on the System V Release 4.0 specification for UNIX systems, making it easier to create and customize startup and shutdown procedures that are consistent across sites and systems. This is in contrast to the simpler BSD-style boot process used by Solaris 1, which lacked a differentiated organization of startup scripts corresponding to distinct system states. The aim of this chapter is to introduce readers to the basic terminology and initialization elements that play an important role in bringing a Solaris system to single- and multiuser run levels or init states, which are mutually exclusive modes of operation. Transitions between init states are managed by the init process. After reading this chapter, Solaris 9 administrators should feel confident in tailoring the startup and shutdown of their own systems, and should have a clear understanding of the boot sequence dependencies when upgrading legacy Solaris 1 systems.