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.