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System Administration Guide: Basic Administration
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Document Information


1.  Oracle Solaris Management Tools (Road Map)

2.  Working With the Solaris Management Console (Tasks)

3.  Working With the Oracle Java Web Console (Tasks)

4.  Managing User Accounts and Groups (Overview)

5.  Managing User Accounts and Groups (Tasks)

6.  Managing Client-Server Support (Overview)

7.  Managing Diskless Clients (Tasks)

8.  Introduction to Shutting Down and Booting a System

9.  Shutting Down and Booting a System (Overview)

10.  Shutting Down a System (Tasks)

11.  Modifying Oracle Solaris Boot Behavior (Tasks)

12.  Booting an Oracle Solaris System (Tasks)

13.  Managing the Oracle Solaris Boot Archives (Tasks)

14.  Troubleshooting Booting an Oracle Solaris System (Tasks)

15.  x86: GRUB Based Booting (Reference)

16.  x86: Booting a System That Does Not Implement GRUB (Tasks)

17.  Working With the Oracle Solaris Auto Registration regadm Command (Tasks)

18.  Managing Services (Overview)

Introduction to SMF

Changes in Behavior When Using SMF

SMF Concepts

SMF Service

Service Identifiers

Service States

SMF Manifests

SMF Profiles

Service Configuration Repository

SMF Repository Backups

SMF Snapshots

SMF Administrative and Programming Interfaces

SMF Command-Line Administrative Utilities

Service Management Configuration Library Interfaces

SMF Components

SMF Master Restarter Daemon

SMF Delegated Restarters

SMF and Booting

SMF Compatibility

Run Levels

When to Use Run Levels or Milestones

Determining a System's Run Level

/etc/inittab File

What Happens When the System Is Brought to Run Level 3

19.  Managing Services (Tasks)

20.  Managing Software (Overview)

21.  Managing Software With Oracle Solaris System Administration Tools (Tasks)

22.  Managing Software by Using Oracle Solaris Package Commands (Tasks)

23.  Managing Patches

A.  SMF Services


Run Levels

A system's run level (also known as an init state) defines what services and resources are available to users. A system can be in only one run level at a time.

The Solaris OS has eight run levels, which are described in the following table. The default run level is specified in the /etc/inittab file as run level 3.

Table 18-2 Solaris Run Levels

Run Level
Init State
Power-down state
To shut down the operating system so that it is safe to turn off power to the system.
s or S
Single-user state
To run as a single user with some file systems mounted and accessible.
Administrative state
To access all available file systems. User logins are disabled.
Multiuser state
For normal operations. Multiple users can access the system and all file system. All daemons are running except for the NFS server daemons.
Multiuser level with NFS resources shared
For normal operations with NFS resources shared. This is the default run level for the Solaris OS.
Alternative multiuser state
Not configured by default, but available for customer use.
Power-down state
To 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.
Reboot state
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).

In addition, the svcadm command can be used to change the run level of a system, by selecting a milestone at which to run. The following table shows which run level corresponds to each milestone.

Table 18-3 Solaris Run Levels and SMF Milestones

Run Level
SMF Milestone FMRI

When to Use Run Levels or Milestones

Under most circumstances, using the init command with a run level to change the system state is sufficient. Using milestones to change system state can be confusing and can lead to unexpected behavior. In addition, the init command allows for the system to be shutdown, so init is the best command for changing system state.

However, booting a system using the none milestone, can be very useful when debugging startup problems. There is no equivalent run level to the none milestone. See How to Boot Without Starting Any Services for specific instructions.

Determining a System's Run Level

Display run level information by using the who -r command.

$ who -r

Use the who -r command to determine a system's current run level for any level.

Example 18-1 Determining a System's Run Level

This example displays information about a system's current run level and previous run levels.

$ who -r
 .    run-level 3  Dec 13 10:10  3  0 S
Output of who -r command
run-level 3
Identifies the current run level
Dec 13 10:10
Identifies the date of last run level change
Also identifies the current run level
Identifies the number of times the system has been at this run level since the last reboot
Identifies the previous run level