Fwd: [Madlug] upgrading to 11.10

[Jim Leinweber]

Donald L. Dietmeyer:
> ... the grub installation does not find my
> primary linux system.  It does find Windows XP; that is what I am
> running at the moment.  But how do I get my primary installation
> to boot so that I can get a bit of work done??

We could offer more detailed advice if we knew more about your
situation, e.g. the disk partition layout, which version of grub
you are running (old grub 1, or new grub 2), which OS is supposed
to own the MBR (windows? old linux? ubuntu 11.10?), etc.

If you are running XP, one option would be to install "EasyBCD"
from neosmart.net.  That can probably find your primary linux
installation, and chain into it.  I think I'd recommend this,
because it is by far the easiest next step.  Then you could just
run:
   sudo update-grub
and be done.

Another option for grub2 jockeys slightly more expert than me
would be to follow boot menu editing advice similar to:
  https://help.ubuntu.com/community/Grub2#Command_Line_and_Rescue_Mode
In particular, if you don't have a separate /boot partition and the
primary root partition was the 3rd one (sda2), then change to
  set root=(hd0,3)
or whatever points at your correct primary root partition,
you could probably (on an ubuntu system, at least) just edit
the rest to
  * delete the search line
  * replace the linux and initrd lines with something like
      linux /vmlinuz root=/dev/sda2 ro
      initrd /initrd.img
I *think* grub2 will follow the symbolic links, so this is for
people who don't remember their exact kernel subversion
and have more clue about the partition number than
about the filesystem UUID.  Once your proper linux has
booted, do the usual
   sudo update-grub
or whatever to permanently fix the boot situation.  Assuming
the typical multiboot case where the primary linux install
owns the MBR.

A third way, and one I've used a lot in the past, is to boot
a live CD, preferably matching your primary linux install,
mount any relevant partitions, and use "chroot" to
switch onto the real linux.  Then you repair the boot
loader from *inside* the real linux, which is ever so much
easier than the convolutions from outside.  Suppose
you have a terminal window open on your live CD,
and "sudo parted -l" shows that you have 3 partitions
you need, with root being /dev/sda6, /boot being
/dev/sda5, and /home being /dev/sdb2.  Then
you'd do something like:

   sudo -i
   mkdir /media/fixme
   mount /dev/sda6 /media/fixme  # root
   cd /media/fixme  # very important
   mount /dev/sda5 boot # /boot relative to root
   mount /dev/sdb2 home # /home relative to root
   for fs in proc dev sys ; do mount -o bind /$fs $fs ; done
   # those 3 are the minimum to allow:
   chroot .  # for the win!
   update-grub  # the moment we've been waiting for

The nice thing about the rather convoluted live CD version is that
is pretty reliable, works on more than one linux distribution, and
works for both people using grub1 and people using grub2.
And because you are running a live linux CD, you can spelunk
on the partitions and filesystems until you figure out exactly
which mount commands you need.  For example, you can
mount the root filesystem and cat etc/fstab (not /etc/fstab)
to figure out if there are other disk partitions that should be
mounted.

Personally, whenever I'm booting more than one version of Linux,
I like the primary Linux to own the MBR, and I make a point of
having all the secondary Linux installs put their boot loaders on
their own root partitions.  It means I got through multiple
stages of boot loaders some times, but it keeps things tidy
and prevents accidents.

If none of the advice so far helps, write back.  Or phone me
at 608-334-7006 tomorrow and describe your situation in
more detail.

> ... I don't get the top bar in 11.10 ...
Nvidia graphics chip, by any chance?  My main home desktop,
alas, does even worse: complete garbage for the unity bar on
the left and the top bar, plus app windows don't work either.
(The cursor is OK, bizarrely enough.)  I've been complaining
about it since alpha3, but they haven't fixed it for me yet.
I'm OK on some other nvidia chips, or a couple of ATI chips,
but one of the 4 machines I use regularly (2 at home, 2 at
work) can't do 11.10.  Maybe precise pangolin will be better
six months hence.

Best wishes,

-- Jim Leinweber, still stuck (for this message) on 11.04

  But multi-booting since 1993!  (And that was
  a fiveway with  DOS 3.1, OS/2, FreeBSD, SLS Linux,
  and later windows 95.  Linux was the only one that could
  successfully chainload all of the others.)