[ltp] Installed Grub to MBR, now still can't boot XP (dual boot config)

[Greg Kimberly]

On Wed, 2007-01-17 at 09:25 -0500, Paul Fox wrote:
> i'm not the original poster, but i've got clarification
> questions, below.  i'm interested because i'm just about to
> start trying to use the XP partition on my X41 for the first time.
> 
> simon wrote:
>  > Greg Kimberly wrote:
>  > > I have a T41 upon which I've installed Ubuntu 6.10 (Edgy). I'm now in
>  > > the seemly unusual situation of being able to boot linux and the
>  > > recovery tools, but not XP. My drive layout is:
>  > > 
>  > > hda1 XP
>  > > hda2 swap
>  > > hda3 ext3 (root of ubuntu)
>  > > hda4 (extended partition)
>  > > 	hda5 rescue and recovery
>  > > 
>  > > I started with 
>  > > 
>  > > title           Windows
>  > >  root            (hd0,0)
>  > >  chainloader     +1
>  > > 
>  > > This boots the rescue and recovery section.
>  > 
>  > you need to add the line:
>  > rootnoverify (hd0,0)
> 
> what does "rootnoverify" do?

my understanding is that it sets the root without attempting to mount
it. See

http://www.gnu.org/software/grub/manual/grub.html#rootnoverify

> 
>  > 
>  > >>From http://thinkwiki.org/wiki/Rescue_and_Recovery
>  > > 
>  > > I got the following for a grub boot profile 
>  > > 
>  > > title           Windows
>  > >  root            (hd0,0)
>  > >  hide            (hd0,4)
>  > >  chainloader     +1
>  > 
>  > Ditch the hidden stuff- you don't need it.
>  > 
>  > > And I then played with trying various hide cmds and now it  won't boot
>  > > at all. I now get an error 17 from grub. Never mind that parted (reached
>  > > via the Ubuntu bootable CD) doesn't show any hidden bits set at all -
>  > > apparently grub sets them in a way that parted can't see? Ack!
>  > 
>  > The partitions are hidden while grub is "running", so they are only 
>  > hidden to systems that grub has booted. It does not change anything on 
>  > your disk.
> 
> is there a "not" missing in the first sentence of the above paragraph?

Interestingly enough, the problem appears to be that somehow the file
system type labels got set to 93 (instead of 83) for the ext3 partition
(and 92 instead of 82 for swap). So grub didn't even bother to look
inside the partition. This must have happened in an earlier attempt on
my part (:-) to use the instructions at: 

http://www.thinkwiki.org/wiki/Rescue_and_Recovery

specifically the use of the parttype cmd. 

> 
>  > 
>  > Reboot to the ubuntu CD, you haven't booted grub on your hdd so the 
>  > partitions are visible- mount your ubuntu partition so you can see 
>  > /boot. Remove the hidden lines from /boot/grub/menu.lst. Reboot and it's 
>  > all fixed.
> 
> why must this be done from the CD?  i thought the original poster could
> boot linux, but not XP.  if he can boot linux, then can't he just make
> the edits from there?

I could boot linux until the changes mentioned above. Now that I've
corrected the partition type flags back I can boot it again. However, I
*still* can't boot XP.

> 
> thank,
> paul
> 
>  > 
>  > > As for the original error (can't boot XP only rescue) I take it that
>  > > when I installed Ubuntu, it squashed the windows boot loader and thus
>  > > there isn't a normal XP bootloader? 
>  > 
>  > Well, yes and no. Windows is semi-helpful in the sense that while their 
>  > bootloaders are completely rubbish, they are required for loading 
>  > windows and store them in the partition (/dev/hda1) rather than the MBR 
>  > (/dev/hda). There is a very simple bootloader installed in the MBR which 
>  > essentially does that same as grub- it chainloads the bootloader on 
>  > /dev/hda1. That is the one you will have wiped and so it doesn't matter.
>  > 
>  > Hope this helps
>  > Simon
>  > -- 
>  > The linux-thinkpad mailing list home page is at:
>  > http://mailman.linux-thinkpad.org/mailman/listinfo/linux-thinkpad
> 
> =---------------------
>  paul fox, pgf@foxharp.boston.ma.us (arlington, ma, where it's 5.9 degrees)