A system run levels (also known as an init state) defines what services & resources are available to users. Only one run level system can be running at a time. The Solaris has 8 run levels & the default run level is specified in the /etc/inittab file as run level 3.
• 0 – Shut down the operating system so that it is safe to turn off power to the system.
• s – Run as a single user with some file systems mounted & accessible.
• 1 – Access all available file systems. User logins are disabled.
• 2 – For normal operations. Multiple users can access the system & all file system. All daemons are running except for the NFS server daemons.
• 3 – For normal operations with NFS resources shared. This is the default run level for the Solaris OS.
• 4 – Not configured by default, but available for customer use.
• 5 – Shut down the operating system so that it is safe to turn off power to the system. If possible, automatically turns off power on systems that support this feature.
• 6 – To shut down the system to run level 0, and then reboot to multiuser level with NFS resources shared (or whatever level is the default in the inittab file).
1. To display run level information except run level 0.
# who -r . run-level 10 Oct 26 18:30 3 0 S
