(Jump to the bonus section on sorting a removed Gnome panel)

I finally got round to doing the Jaunty->Karmic upgrade on a troublesome machine. Well, re-doing. I made an abortive attempt to install it on this particular exhibit of electronic arthritis back before I left for Barcelona, which ended in me reinstalling 9.04.

Anyway, for one reason or another the upgrade failed or was interrupted and so I was left with a machine that would not boot. Well, it would do a good chunk of the boot process, but fail at an init item (init_bottom, I think). mountall was exiting with code 127, complaining:

process mountall (787) exited with code 127:
undefined symbol: udev_monitor_filter_add_match_subsystem_devtype
*

Quite a mouthful, in other words. Even booting into “recovery mode” didn’t give me a working console. Next step: try a liveCD. The same problem was reported by niroht of the ubutuforums here. However, his explanation is a bit brief, and misses out a couple gotchas.

So, you’ve got a problem with mountall, and you’ve also got a 9.10 liveCD. Here’s how to sort it:

  1. Boot from the livecd
  2. Call up a terminal (gnome-terminal or xterm).
  3. Chroot your usual install partition. GParted, under “Administration” can help you determine what this is. Mine was /dev/sda3. What I did was:
    • sudo su
    • mkdir /newroot
    • mount /newroot /dev/sda3
    • chroot /newroot <- chrooting my install parition
    • mount /proc <- important! not mounting /proc causes all sorts of problems.

    Now you’re chrooted and ready to continue. I have a separate /boot partition as well, but I updated this later to save faffing at this stage.

  4. Sort the botched upgrade! I ran first dpkg --configure -a, then to be sure, apt-get -f install. Finally, I ran apt-get dist-upgrade, which upgraded a *lot* of packages (~700 I think).

Now, if your /boot prtition resides on the same partition, you’re done here. If not, you have to mount it and copy the new kernel images and updated menu.lst. Strictly speaking, this should be possible to set up when doing the chroot above, but I couldn’t remember how to do it at the time. Make sure if you are merging the menu.lst that the contents are correct – check the UUIDs or partition references are correct!

Bonus! Restore the default gnome-panel if you accidentally delete

So once I was done with the fixed upgrade I booted, and got a slightly messed up top Gnome panel. Two volume icons, and no network icon. In my attempt to sort it, I clicked cack-handedly and removed the entire panel. Rather than repopulate it manually, I followed the advice of another ubuntuforums thread:

gconftool-2 --shutdown
rm -rf ~/.gconf/apps/panel
pkill gnome-panel

And that was the panel restored to default!

* (Previously listed as “undev_mknitor_filter_add_match_sebsystem_devtype”, as it appeared on the screen. Part of the electronic arthritis is (I think) in the graphics card, which causes all sorts of odd things to happen to the pre-boot text. Must photo it sometime.)