System Administration Guide: Basic Administration

x86: Introducing Fast Reboot

This feature is available, starting with build 100 of the Solaris Express Community Edition release, and in the OpenSolaris 2008.11 OS.

Fast Reboot implements an in-kernel boot loader that loads the kernel into memory, then switches to that kernel, thus enabling the reboot process to occur within seconds. With Fast Reboot, you can reboot to a new kernel without experiencing the long delays that can be imposed by the BIOS and boot loader. The ability to fast reboot a system drastically reduces down time and improves efficiency.

Note –

Fast Reboot is currently not available on the SPARC platform.

The following sections provide a general overview of the Fast Reboot feature. For task related information, see Using Fast Reboot on the x86 Platform (Task Map).

Modifications to the reboot Command to Support Fast Reboot

To support Fast Reboot, the reboot command has been modified to include two new options:


Initiates the fast reboot process, when used with the reboot command.


Initiates a fast reboot to an alternate boot environment (BE), when used in conjunction with the -f option,

Note –

The -e option cannot be used to fast reboot to an alternate BE in the OpenSolaris 2008.11 release. For instructions on initiating a fast reboot to an alternate BE in this release, see x86: Initiating a Fast Reboot to an Alternate Boot Environment in the OpenSolaris 2008.11 OS.

For more information, see the reboot(1M) man page.

Implementation of the quiesce Function

The system's capability to bypass the firmware when booting a new OS image has dependencies on device drivers' implementation of a new device operation entry point, quiesce. On supported drivers, this implementation quiesces a device, so that at completion of the function, the driver no longer generates interrupts or access memory. This implementation also resets the device to a hardware state, from which the device can be correctly configured by the driver's attach routine, without a power cycle of the system or being configured by the firmware. For more information about this functionality, see the quiesce(9E) and dev_ops(9S) man pages.

Note –

Not all device drivers implement the quiesce function. For troubleshooting instructions, see x86: Troubleshooting Conditions That Might Prevent Fast Reboot From Working.

New uadmin Function

Other changes that support Fast Reboot on the x86 platform include the new uadmin function, AD_FASTREBOOT. This function resets the system, enabling the reboot command to bypass the BIOS and the boot loader phases.

Note –

The uadmin 2 8 command has limited functionality. If the command is used to facilitate a fast reboot of the system, neither the boot archive, nor the menu.lst file are updated. For this reason, the reboot -f command is the preferred method for initiating a fast reboot.

For more information, see the uadmin(2)man page.