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Booting and Shutting Down Oracle Solaris on x86 Platforms     Oracle Solaris 11 Information Library
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About This Book

1.  Booting and Shutting Down an x86 Based System (Overview)

What's New in Booting and Shutting Down a System

Administratively Provided driver.conf Files

Bitmapped Console Support

Boot and Shutdown Animation

Fast Reboot

x86: Removal of Support for 32-Bit Kernel

Booting and Shutting Down an x86 Based System (Topic Map)

Guidelines for Booting an x86 Based System

Reasons to Boot a System

Service Management Facility and Booting

Changes in Boot Behavior When Using SMF

How Run Levels Work

What Happens When a System Is Booted to a Multiuser State (Run Level 3)

When to Use Run Levels or Milestones

Overview of the Oracle Solaris Boot Architecture

How the x86 Boot Process Works

GRUB-Based Booting

GRUB Components

Purpose and Function of the GRUB Menu

GRUB Device-Naming Conventions

x86 and GRUB Boot Terminology

2.  Booting an x86 Based System to a Specified State (Tasks)

3.  Shutting Down a System (Tasks)

4.  Rebooting an x86 Based System (Tasks)

5.  Booting an x86 Based System From the Network (Tasks)

6.  Modifying Boot Parameters on an x86 Based System (Tasks)

7.  Creating, Administering, and Booting From ZFS Boot Environments on x86 Platforms (Tasks)

8.  Keeping an x86 Based System Bootable (Tasks)

9.  Troubleshooting Booting an x86 Based System (Tasks)


How Run Levels Work

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.

Oracle Solaris 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 1-3 Oracle 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 systems. 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.
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 a multiuser level with NFS resources shared (or whatever run 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 1-4 Run Levels and SMF Milestones

Run Level
SMF Milestone FMRI

What Happens When a System Is Booted to a Multiuser State (Run Level 3)

  1. The init process is started and reads the properties defined in the svc:/system/environment:init SMF service to set any environment variables. By default, only the TIMEZONE variable is set.

  2. Then, init reads the inittab file and does the following:

    1. Executes any process entries that have sysinit in the action field so that any special initializations can take place before users log in to the system.

    2. Passes the startup activities to svc.startd.

    For a detailed description of how the init process uses the inittab file, see the init(1M) man page.

When to Use Run Levels or Milestones

In general, changing milestones or run levels is an uncommon procedure. If it is necessary, using the init command to change to a run level will change the milestone as well and is the appropriate command to use. The init command is also good for shutting down a system.

However, booting a system using the none milestone can be very useful for debugging startup problems. There is no equivalent run level to the none milestone. For more information, see How to Boot Without Starting Any Services in Oracle Solaris Administration: Common Tasks.