Booting and Shutting Down an Oracle Solaris System (Overview)

The Oracle Solaris x86 and SPARC boot architectures share the following fundamental characteristics:

• Use of a boot archive

  The boot archive is a ramdisk image that contains all of the files that are required for booting a system. For more information, see Description of the Oracle Solaris Boot Archives in Booting and Shutting Down Oracle Solaris on SPARC Platforms.

• Use of a boot administration interface to maintain the integrity of the Oracle Solaris boot archives

  The bootadm command handles the details of boot archive update and verification. During an installation or upgrade, the bootadm command creates an initial boot archive. During the process of a normal system shutdown, the shutdown process compares the boot archive's contents with the root file system. If there have been updates to the system such as drivers or configuration files, the boot archive is rebuilt to include these changes so that upon reboot, the boot archive and root file system are synchronized. You can use the bootadm command to manually update the boot archive. For instructions, see Maintaining the Integrity of the Boot Archives in Booting and Shutting Down Oracle Solaris on SPARC Platforms.

  For more information, see the bootadm(1M) and boot(1M) man pages.

• Use of a ramdisk image as the root file system during installation

  The ramdisk image is derived from the boot archive and then transferred to the system from the boot device.

  In the case of a software installation, the ramdisk image is the root file system that is used for the entire installation process. The ramdisk file system type can be a High Sierra File System (HSFS).

For more information about SPARC boot processes, see Description of the SPARC Boot Process in Booting and Shutting Down Oracle Solaris on SPARC Platforms.

For more information about boot processes on the x86 platform, see How the x86 Boot Process Works in Booting and Shutting Down Oracle Solaris on x86 Platforms.

GRUB Based Booting

In Oracle Solaris, the open source GRand Unified Bootloader (GRUB) is the default boot loader on the x86 platform. GRUB is responsible for loading a boot archive into the system's memory. A boot archive is a collection of critical files that is needed during system startup before the root file system is mounted. The boot archive is the interface that is used to boot Oracle Solaris.

GRUB implements a menu interface that includes boot options that are predefined in a configuration file called the menu.lst file. GRUB also has a command-line interface that is accessible from the GUI menu interface that can be used to perform various boot functions, including modifying default boot parameters.

The menu that is displayed when you boot an x86 based system is the GRUB menu. This menu is based on configuration information that is in the GRUB menu.lst file. When the boot sequence starts, the GRUB menu is displayed. Unless you interrupt the boot sequence, the default entry (typically the first entry in the menu.lst file) is booted by default.

You can edit the GRUB menu at boot time to either boot a different operating system or modify the parameters of the default boot entry. To do so, type e as soon as the GRUB menu is displayed. Typing e interrupts the boot process and takes you to the GRUB edit menu, where you can select another OS to boot or modify default boot parameters for the default boot entry. Note that the modified boot behavior persists only until the next time the system is booted.

For task-related information, see Booting and Shutting Down Oracle Solaris on x86 Platforms.

Management of Boot Services by the Service Management Facility

With the introduction of SMF, the boot process now creates fewer messages. Also, services do not display a message by default when they are started. All of the information that was provided by the boot messages can now be found in a log file for each service that is in /var/svc/log. You can use the svcs command to help diagnose boot problems. To generate a message when each service is started during the boot process, use the -v option with the boot command.

Most of the features that are provided by SMF occur behind the scenes, so users are not typically aware of these features. Other features are accessed by new commands.

For more information, see SMF and Booting.