Failure Recovery: Falling Back to the Original Boot Environment (Command-Line Interface)

If a failure is detected after upgrading or if the application is not compatible with an upgraded component, fall back to the original boot environment by using one of the following procedures, depending on your platform. For SPARC based systems, the first procedure runs luactivate to switch back to the original boot environment. If the first procedure fails, use the second procedure to boot from a CD-ROM or a net image. For IA based systems, choose the procedure that is based on where the root (/) file systems are mounted, on the same or different physical disks.

SPARC: To Fall Back to the Original Boot Environment

If you experience a failure while booting the new boot environment, use this procedure to fall back to the original boot environment.

1. Log in as superuser.

2. Type:

   # /sbin/luactivate

   • If this command fails to display a prompt, proceed to SPARC: To Fall Back to the Original Boot Environment by Using a CD or Net Image.

   • If the prompt is displayed, continue.

3. At the prompt, type:

   Do you want to fallback to activate boot environment <disk name> (yes or no)? yes

   A message displays that the fallback activation is successful.

SPARC: To Fall Back to the Original Boot Environment by Using a CD or Net Image

If you were unsuccessful at using luactivate in the previous procedure, use this procedure to boot from a CD or a net image. You need to mount the root (/) slice from the last active boot environment. Then run the luactivate command, which makes the switch. When you reboot, the last active boot environment is up and running again.

1. At the OK prompt, boot the machine to single-user state from the installation CD, the network, or a local disk:

   OK boot cdrom -s

   or

   OK boot net -s

   or

   OK boot disk -s

   disk	The name of the disk and the slice where a copy of the operating system resides, for example disk1:A.

2. If necessary, check the integrity of the file system for the fallback boot environment root (/).

   # fsck mount point

   mount_point

   A root file system that is known and reliable

3. Mount the active boot environment root slice to some directory (such as /mnt/sbin):

   # mount logical_device_name /mnt/sbin

   logical_device_name

   Any device, including a Veritas VxVM volume or Solstice DiskSuite metadevice

4. From the active boot environment root slice, type:

   # /mnt/sbin/luactivate

   luactivate activates the previous working boot environment and indicates the result.

5. Unmount /mnt/sbin

   # umount logical_device_name /mnt/sbin

   logical_device_name

   Any device, including a Veritas VxVM volume or Solstice DiskSuite metadevice

6. Reboot.

   # init 6

   The previous working boot environment becomes the active boot environment.

x86: To Fall Back With Boot Environments on Different Disks

If you experience a failure while booting the new boot environment and the root (/) file systems for the boot environments are on different physical disks, use the following procedure to fall back to the original boot environment.

1. Reboot the machine and enter the appropriate BIOS menus.

   • If your boot devices are SCSI, refer to documentation on your SCSI controller on how to enter the SCSI BIOS.

   • If the boot devices are maintained by the system BIOS, refer to system BIOS documentation on how to enter the system BIOS.

2. Follow the appropriate BIOS documentation to change the boot device back to the original boot environment's boot device.

3. Save the BIOS changes.

4. Exit BIOS to begin the boot process.

5. At the OK prompt, boot the machine to single-user state.

   OK b -s

6. Type:

   # /sbin/luactivate

7. Reboot.

   # init 6

x86: To Fall Back With Boot Environments on the Same Disk

If you experience a failure while booting and the root (/) file systems are on the same physical disk, use the following procedure to fall back to the original boot environment. You need to mount the root (/) slice from the last active boot environment. Then run the luactivate command, which makes the switch. When you reboot, the last active boot environment is up and running again.

1. Decide how to boot the system:

   • Access the Solaris Device Configuration Assistant from the Solaris 8 Installation CD, Solaris 8 Software 1 of 2 CD, or from a net image of the CD. Your system's BIOS must support booting from a CD.

   • Insert the Solaris 8 Device Configuration Assistant Intel Platform Edition diskette. The boot diskette software can be downloaded and copied to a diskette from the Solaris Developer Connection at: soldc.sun.com/support/dirvers/dca_diskettes.

   • Access the Solaris Device Configuration Assistant from the network using Pre-boot eXecution Environment (PXE). PXE enables you to boot a system directly from the network without using the boot diskette. The system must support PXE. Enable the system to use PXE by using the systems's BIOS setup tool or the network adapter's configuration setup Tool.

   Follow the directions on screen until the Current Boot Parameters menu is displayed.

2. At the OK prompt, boot the machine to single-user state.

   OK b -s

3. If necessary, check the integrity of the file system for the fallback boot environment root (/).

   # fsck mount point

   mount_point

   A root file system that is known and reliable

4. Mount the active boot environment root slice to some directory (such as /mnt/sbin):

   # mount logical_device_name /mnt/sbin

   logical_device_name

   Any device, including a Veritas VxVM volume or Solstice DiskSuite metadevice

5. From the active boot environment root slice, type:

   # /mnt/sbin/luactivate

   luactivate activates the previous working boot environment and indicates the result.

6. Unmount /mnt/sbin.

   # umount logical_device_name /mnt/sbin

   logical_device_name

   Any device, including a Veritas VxVM volume or Solstice DiskSuite metadevice

7. Reboot.

   # init 6

   The previous working boot environment becomes the active boot environment.