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 9 DVD or the Solaris 9 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 9 Device Configuration Assistant x86 Platform Edition diskette into the system's diskette drive.

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     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 9 x86 Platform Edition DVD or Solaris 9 Software 2 of 2 x86 Platform Edition CD by using this procedure: Appendix I, x86: Preparing to Boot From the Solaris 9 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.

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   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.