Bug#614173: release-notes: "chainload to grub2 once" is a good option for people with remote boxes

["Karl O. Pinc" <kop@meme.com>]

Package: release-notes
Severity: wishlist

Hi,

People who do not have immediate physical access to their
boxes may be nervous about testing the chainloading
of grub2.  It'd be nice to have something in an appendix
that tells them how to use grub1 to chainload boot grub2
only once, and fallback to regular booting with grub1
That way if the chainload fails a simple power cycle
will bring their box back up.

The technique is shown here, vis the grub1
"Booting once-only" and "Booting fallback systems"
info page (the paths and args are for example only):

  # Boot the saved default
  default saved
  fallback 0
  timeout 10

  title Debian squeeze kernel
  root (hd0,0)
  kernel /boot/vmlinuz root=/dev/sda1 
  initrd /boot/initrd
  # If we're using this to boot save it as the default
  savedefault 0

  title Debian squeeze kernel (rescue mode)
  root (hd0,0)
  kernel /boot/vmlinuz root=/dev/sda1 single
  initrd /boot/initrd
  savedfault fallback
  
  title Chainload to grub2
  chainloader /boot/grub2
  # After trying grub2 once go back booting with grub1.
  savedefault fallback

Then to try chainloading with grub2 the admin must run:

# grub-set-default 3 ;# 3 in this case being chainload grub2

Before trying grub2 the admin can arrange for someone at
the remote location to power cycle should there be a
problem.

-- System Information:
Debian Release: 5.0.8
  APT prefers oldstable
  APT policy: (500, 'oldstable')
Architecture: i386 (i686)

Kernel: Linux 2.6.26-2-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash