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 DVD-ROM, CD-ROM, or net image. For x86 based systems, choose the procedure that is based on where the root (/) file systems are mounted, on the same or different physical disks.

To Fall Back Despite Successful New Boot Environment Creation

Use this procedure when you have successfully activated your new boot environment, but are unhappy with the results.

1. Log in as superuser.

2. Type:

   # /usr/sbin/luactivate BE_name

   BE_name

   Specifies the name of the boot environment to be activated

3. Reboot.

   # init 6

   The previous working boot environment becomes the active boot environment.

SPARC: To Fall Back From a Failed Boot Environment Activation

• If you experience a failure while booting the new boot environment and can boot the original boot environment in single-user mode, use this procedure to fall back to the original boot environment.

• If you need to boot from media or a net installation image, see SPARC: To Fall Back to the Original Boot Environment by Using a DVD, CD, or Net Installation Image.

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

   OK boot cdrom -s

   or

   OK boot net -s

   or

   OK boot device_name -s

   device_name

   Specifies the name of devices from where the system can boot, for example /dev/dsk/c0t0d0s0

2. Type:

   # /sbin/luactivate BE_name

   BE_name

   Specifies the name of the boot environment to be activated

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

4. Reboot.

   # init 6

   The previous working boot environment becomes the active boot environment.

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

Use this procedure to boot from a DVD, CD, or a net installation 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 Solaris DVD, Solaris Installation CD, the network, or a local disk:

   OK boot cdrom -s

   or

   OK boot net -s

   or

   OK boot device_name -s

   device_name

   Specifies the name of the disk and the slice where a copy of the operating system resides, for example /dev/dsk/c0t0d0s0

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

   # fsck device_name

   device_name

   Specifies the location of the root (/) file system on the disk device of the boot environment you want to fall back to. The device name is entered in the form of /dev/dsk/cwtxdysz.

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

   # mount device_name /mnt

   device_name

   Specifies the location of the root (/) file system on the disk device of the boot environment you want to fall back to. The device name is entered in the form of /dev/dsk/cwtxdysz.

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

   # umount /mnt

6. Reboot.

   # init 6

   The previous working boot environment becomes the active boot environment.

x86: To Fall Back With Boot Environments on Different Disks

You might experience a failure while booting the new boot environment. If 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 if different.

3. Save the BIOS changes.

4. Exit BIOS to begin the boot process.

5. Type b -s to boot the machine to single-user state.

6. Type:

   # /sbin/luactivate

7. Reboot.

   # init 6

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

You might experience a failure while booting. If 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.

   • If you boot from the Solaris DVD or the Solaris Installation CD, insert the disc. Your system's BIOS must support booting from a DVD or CD.

   • If you boot from the network, use Preboot Execution Environment (PXE) network boot. 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.

   • If you boot from a diskette, insert Solaris Device Configuration Assistant x86 Platform Edition diskette into the system's diskette drive.

     ---

     x86 only –

     You can copy the Device Configuration Assistant software to a diskette by the following methods:

     • Copy the software to a diskette from the Solaris x86 Platform Edition DVD or Solaris Software 2 of 2 x86 Platform Edition CD by using this procedure: Appendix I, x86: Preparing to Boot From the Solaris Device Configuration Assistant or the Network (Tasks).

     • Download and copy the software to a diskette from the Solaris Developer Connection at http://soldc.sun.com/support/drivers/dca_diskettes.

     ---

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

2. Type b -s to boot the machine to single-user state.

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 device_name /mnt/sbin

   device_name

   Specifies the location of the root (/) file system on the disk device of the boot environment you want to fall back to. The device name is entered in the form of /dev/dsk/cwtxdysz.

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 device_name /mnt/sbin

   device_name

   Specifies the location of the root (/) file system on the disk device of the boot environment you want to fall back to. The device name is entered in the form of /dev/dsk/cwtxdysz.

7. Reboot.

   # init 6

   The previous working boot environment becomes the active boot environment.