Rescue and Recovery

From ThinkWiki
Revision as of 14:23, 31 January 2006 by Wyrfel (Talk | contribs) (Proper MBR)

Jump to: navigation, search

Rescue and Recovery version 3.0 consists of a bootable partition containing various system recovery tools, including full recovery of the preinstalled Windows XP partition. It can be activated by pressing the ThinkPad, Access IBM or ThinkVantage Button during system boot. It contains a FAT filesystem (labeled "IBM_SERVICE"), and has partition type 0x12 ("Compaq diagnostics" in fdisk).

As opposed to a Hidden Protected Area Recovery partitions are ordinary partitions, accessible through the partition table. As they are ordinary partitions they are accessible by ordinary partitioning tools. They should be dealt carefully with.

Proper MBR

Consideration 6 of the Readme states:

"The Master Boot Record (MBR) must be configured properly for the Rescue and Recovery application to function properly. When possible, the Rescue and Recovery application attempts to ensure the proper configuration of the MBR. This can only occur if the Rescue and Recovery application is installed after other applications that requires the MBR."

To translate that, people found that the following is the case:

  • the default MBR seems to ignore the active bit and always boots the first partition instead
  • the default MBR contains code to catch a press of the appropriate button during bootup and boot the R&R partition in that case
  • the R&R software assumes that the first partition contains Windows
  • the R&R partition needs to be of type 0x0b (FAT32)

Apparently, the MBR is not "configured properly" if LILO or GRUB has been installed in it. Since they do not include code for triggering the button press, it is not possible to invoke Rescue and Recovery by pressing the appropriate button during system boot, once LILO or GRUB have been installed in the MBR.

You can, however, boot the Rescue and Recovery partition from within GRUB. It has been reported, that many Linux distributions change the recovery partitions type to 0x12 (Compaq disgnostics), which, if you try booting it, results in an error message "c000021a, Fatal System Error".

To avoid that and make sure the recovery partition always is of the right type, add a line to change the partition type to 0x0b to the recovery partitions entry in your /boot/grub/menu.lst. Assuming your recovery partition is the second partition, it should look like this:

 title           IBM Rescue and Recovery
 root            (hd0,1)
 parttype        (hd0,1) 0x0b
 unhide          (hd0,1)
 chainloader     +1

We also add an unhide line here because we are going to hide the recovery partition on every boot of Windows, so we need to unhide it, when the recovery partition is booted. This is because if we wouldn't hide the partition when booting Windows, it would be visible and accessable there and that's not what we want. So, assuming that Windows is on the first partition, the Windows entry should now look like this:

 title           Windows
 root            (hd0,0)
 hide            (hd0,1)
 chainloader     +1

Now you should be able to boot the R&R partition from withing GRUB, residing in your MBR.

External Sources

External Sources

Models featuring this technology