вынужденного update-grub (косяк релиза, проблема с grub'ом)

lrwxrwxrwx 1 root root 10 2010-05-31 08:42 38FC67F8FC67AF36 -> ../../sdb2
lrwxrwxrwx 1 root root 10 2010-05-31 08:42 9A54C53D54C51D3F -> ../../sdb5
lrwxrwxrwx 1 root root 10 2010-05-31 08:42 AE784E07784DCF31 -> ../../sdb1
lrwxrwxrwx 1 root root 10 2010-05-31 08:42 C630C30430C2FA87 -> ../../sda1

The Quick-and-Dirty Solution

Method 1
To boot Windows XP installed to (hd1,1), use the following menuentry (in a script you write as a text file in the folder /etc/grub.d):

# Method 1 -- a safe, sure way to do it
# This method applies to Windows and to FreeDOS
# Windows XP on sdb1 (= (hd1,1)
menuentry “Windows XP on sdb1, by chainloader” {
drivemap (hd0) (hd1)
drivemap (hd1) (hd0)
set root=(hd0)
chainloader (hd1,1)+1
}

=> The drivemap command in GRUB 2 replaces the map command in GRUB Legacy.
=> That's all you need to know to make your grub.cfg work.
You can stop reading now, if you wish. :)

- - - - -
Method 2 applies to booting Windows on a non-first hard drive; it does not apply to FreeDOS:

# Method 2
# This method applies to Windows
# This method does NOT apply to FreeDOS
# Windows XP on sdb1 (= (hd1,1)
menuentry “Windows XP on sdb1, by chainloader” {
drivemap (hd1) (hd0)
set root=(hd1,1)
chainloader +1
}

IMPORTANT:
The line
drivemap (hd1) (hd0)
is my idea; in the grub-devel correspondence, it was the opposite:
drivemap (hd0) (hd1)

What this means for you
> You can stick with the safe method, Method 1.
> If you choose to use the more compact Method 2, doing it my way or their way, and if your PC hangs up, not able to boot into Windows, press the re-set button on your PC to re-boot, then boot into your Kubuntu 9.10 and fix your grub.cfg so it tries another way (e.g., switch from drivemap (hd1) (hd0) to drivemap (hd0) (hd1) or vice versa). Or, re-boot using re-set button, then experiment at the GRUB CLI by pressing the "c" key and manually trying another way to see what will work (at the grub>, don't forget to use the boot command as your last command: grub>boot).


Technical notes

-- The drivemap command in GRUB 2 replaces the map command in GRUB Legacy.

-- You should use an up-to-date version of GRUB 2 (1.97xx). You can get it from 9.10 Karmic.

-- The switch -s should also work:

# Method 1 -- a safe, sure way to do it
# This method applies to Windows and to FreeDOS
menuentry “Windows XP on sdb1, by chainloader” {
drivemap -s (hd0) (hd1)
set root=(hd0)
chainloader (hd1,1)+1
}

where the line
drivemap -s (hd0) (hd1)
means:
drivemap (hd0) (hd1)
drivemap (hd1) (hd0)

-- If doing this at the GRUB CLI (grub>), you must (always) issue the boot command as your last command, in this case after the chainloader command:
drivemap -s (hd0) (hd1)
set root=(hd0)
chainloader (hd1,1)+1
grub>boot