In addition to controlling the power state of the host, you can also control how and when the OS is booted.
When the host is powered on, it can be in one of these states:
Booted – The OS is running in one of these levels:
3 – The OS is running in multiuser mode with all resources enabled.
S – The OS is running in single-user mode, and some resources are not enabled.
At the OpenBoot prompt – The OS is not running. You communicate with the OpenBoot firmware on the host. See Obtaining the OpenBoot Prompt.
By default, the host automatically attempts to boot when the host is reset or powered on. The host first seeks a local boot drive. If the host cannot boot from the drive, the host attempts to boot from the network. See Boot the OS (Oracle ILOM).
These steps describe the high-level boot sequence:
A host reset is initiated.
OpenBoot runs and OpenBoot parameters are read.
The primary OpenBoot parameters and default values that determine how the server boots are:
diag-switch? false
auto-boot? true
boot-device disk net
See View All OpenBoot Parameters for more information.
A boot block is read from the boot device to locate a boot program.
The boot program loads the kernel into memory.
The kernel is executed and takes control.
You can configure booting parameters from the OS or at the ok prompt. You can also affect the boot behavior through Oracle ILOM.
For more detailed information about OpenBoot startup and boot sequences, see Start-up Sequence in Oracle OpenBoot 4.x Administration Guide.
For more information about the boot process and how to configure booting in Oracle Solaris: