(Optional) To Fall Back to the Source Boot Environment

The following procedures for falling back depend on your new boot environment activation situation:

• For SPARC based systems:

  • The activation is successful, but you want to return to the original boot environment. See Example 9–1.

  • The activation fails and you can boot back to the original boot environment. See Example 9–2.

  • The activation fails and you must boot back to the original boot environment by using media or a net installation image. See Example 9–3.

• For x86 based systems, starting with the Solaris 10 1/06 release and when you use the GRUB menu:

  • The activation fails, the GRUB menu is displayed correctly, but the new boot environment is not bootable. See Example 9–4

  • The activation fails and the GRUB menu does not display. See Example 9–5.

Example 9–1 SPARC: To Fall Back Despite Successful Boot Environment Creation

In this example, the original c0t4d0s0 boot environment is reinstated as the active boot environment although it was activated successfully. The device name is first_disk.

# /sbin/luactivate first_disk 
# init 6

Example 9–2 SPARC: To Fall Back From a Failed Boot Environment Activation

In this example, the new boot environment was not bootable. You must return to the OK prompt before booting from the original boot environment, c0t4d0s0, in single-user mode.

OK boot net -s
# /sbin/luactivate first_disk
Do you want to fallback to activate boot environment c0t4d0s0 
(yes or no)? yes
# init 6

The original boot environment, c0t4d0s0, becomes the active boot environment.

Example 9–3 SPARC: To Fall Back to the Original Boot Environment by Using a DVD, CD, or Net Installation Image

In this example, the new boot environment was not bootable. You cannot boot from the original boot environment and must use media or a net installation image. The device is /dev/dsk/c0t4d0s0. The original boot environment, c0t4d0s0, becomes the active boot environment.

OK boot net -s
# fsck /dev/dsk/c0t4d0s0
# mount /dev/dsk/c0t4d0s0 /mnt 
# /mnt/sbin/luactivate
Do you want to fallback to activate boot environment c0t4d0s0 
(yes or no)? yes
# umount /mnt 
# init 6

Example 9–4 x86: To Fall Back to the Original Boot Environment By Using the GRUB Menu

Starting with the Solaris 10 1/06 release, the following example provides the steps to fall back by using the GRUB menu.

In this example, the GRUB menu is displayed correctly, but the new boot environment is not bootable. To enable a fallback, the original boot environment is booted in single-user mode.

1. Become superuser or assume an equivalent role.

2. To display the GRUB menu, reboot the system.

   # init 6

   The GRUB menu is displayed.

   GNU GRUB version 0.95 (616K lower / 4127168K upper memory) +-------------------------------------------------------------------+ |Solaris | |Solaris failsafe | |second_disk | |second_disk failsafe | +-------------------------------------------------------------------+ Use the ^ and v keys to select which entry is highlighted. Press enter to boot the selected OS, 'e' to edit the commands before booting, or 'c' for a command-line.

3. From the GRUB menu, select the original boot environment. The boot environment must have been created with GRUB software. A boot environment that was created before the Solaris 10 1/06 release is not a GRUB boot environment. If you do not have a bootable GRUB boot environment, then skip to Example 9–5.

4. Edit the GRUB menu by typing: e.

5. Select kernel /boot/multiboot by using the arrow keys and type e. The grub edit menu is displayed.

   grub edit>kernel /boot/multiboot

6. Boot to single user mode, by typing -s.

   grub edit>kernel /boot/multiboot -s

7. Boot and mount the boot environment. Then activate it.

# b
# fsck /dev/dsk/c0t4d0s0
# mount /dev/dsk/c0t4d0s0 /mnt 
# /mnt/sbin/luactivate
Do you want to fallback to activate boot environment c0t4d0s0
(yes or no)? yes
# umount /mnt
# init 6

Example 9–5 x86: To Fall Back to the Original Boot Environment With the GRUB Menu by Using the DVD or CD

Starting with the Solaris 10 1/06 release, the following example provides the steps to fall back by using the DVD or CD.

In this example, the new boot environment was not bootable. Also, the GRUB menu does not display. To enable a fallback, the original boot environment is booted in single-user mode.

1. Insert the Solaris Operating System for x86 Platforms DVD or Solaris Software for x86 Platforms - 1 CD.

2. Become superuser or assume an equivalent role.

3. Boot from the DVD or CD.

   # init 6

   The GRUB menu is displayed.

   GNU GRUB version 0.95 (616K lower / 4127168K upper memory) +-------------------------------------------------------------------+ |Solaris 10 5/09 | |Solaris 10 5/09 Serial Console ttya | |Solaris 10 5/09 Serial Console ttyb (for lx50, v60x and v65x | +-------------------------------------------------------------------+ Use the ^ and v keys to select which entry is highlighted. Press enter to boot the selected OS, 'e' to edit the commands before booting, or 'c' for a command-line.

4. Wait for the default option to boot or choose any option displayed.

   The installation screen is displayed.

   +-------------------------------------------------------------------+ |Select the type of installation you want to perform: | | | | 1 Solaris Interactive | | 2 Custom JumpStart | | 3 Solaris Interactive Text (Desktop session) | | 4 Solaris Interactive Text (Console session) | | 5 Apply driver updates | | 6 Single user shell | | | | Enter the number of your choice followed by the <ENTER> key.| | Alternatively, enter custom boot arguments directly. | | | If you wait 30 seconds without typing anything, | | an interactive installation will be started. | +----------------------------------------------------------------- --+

5. Choose the “Single user shell” option.

   The following message is displayed.

   Do you wish to automatically update the boot archive? y /n

6. Type: n

   Starting shell... #

   You are now in single user mode.

7. Mount the boot environment. Then activate and reboot.

   # fsck /dev/dsk/c0t4d0s0 # mount /dev/dsk/c0t4d0s0 /mnt # /mnt/sbin/luactivate Do you want to fallback to activate boot environment c0t4d0s0 (yes or no)? yes # umount /mnt # init 6