Guide - Upgrading Ubuntu 10.04 to 10.10

This post describes the not-so-smooth update from Ubuntu 10.04 to 10.10. The "One Click Upgrade" did not really work here :P Took me several hours to get this right, and I used several backups to restore my system after bad attempts. Hopefully I'll save you some time and effort on how to do this =)

If the usual upgrade works for you, follow it - the steps here were done because the regular upgrade didn't work (slow internet connection, and some more problems).

Info: I'm running 32-bit Ubuntu, inside Virtualbox (a VM) under Windows XP SP3 host.
Note: These are the steps that worked for me. I can't guarantee that they will work on your system, and you should know what you are doing. ALWAYS BACKUP BEFORE UPGRADING!

1. Go to the Update Manager (under System->Administration) and install all the updates (except for the new Ubuntu version) by clicking the Install Updates button.
2. Download the Ubuntu Alternate Installation CD iso file (I downloaded it by torrent from here). Now, either burn it on a CD and then insert the CD, or mount it directly if you know how.
3. A dialog should pop - Choose the upgrade option. If a dialog does not pop, run the cdromupgrade program (inside the root directory of the cd) as root (using sudo).
4. When it asks about using the network, say no. This will allow us to install directly from the cd and not from the web (which is slower - that's why we downloaded a torrent in the first place)
5. You may get the following error:
   

   An unresolvable problem occurred while calculating the upgrade:
   Can not mark 'ubuntu-desktop' for upgrade
   
    This can be caused by:
    * Upgrading to a pre-release version of Ubuntu
    * Running the current pre-release version of Ubuntu
    * Unofficial software packages not provided by Ubuntu
   
   If none of this applies, then please report this bug against the 'update-manager' package and include the files in /var/log/dist-upgrade/ in the bug report.

   In that case, close the upgrade process. Open a console and type
   sudo apt-get remove ubuntu-dektop
   
   Now, repeat from step 2 (inserting the CD). You may get an error saying that a required package ubuntu-desktop can not be installed. Ignore it (as if you have a choice :D)
6. The installation should now begin!
   Note - you may get a dialog or two asking you about replacing some configuration files, towards the end of the installation (8 minutes from the end in my case). Make sure to look once in a while to see such dialogs that need answers.
    When the installation will finish, you are probably going to get error messages about gnome-orca not being installed correctly. We'll fix these in a moment.
7. When the installation is done with/without errors, restart your machine if it hasn't done it by itself.
8. When the machine is up again, make sure the ubuntu installation CD is still mounted. Open the console and type:
   sudo apt-get update
9. If you had any errors during the upgrade (i.e. it said that it finished, but with errors), run the following command:
   sudo apt-get -f install

Now, if you are not using Virtualbox (if you are, you'll know it), you are done! [*see update below]

If you are using Virtualbox, then like after every serious upgrade, you'll need to re-install the guest additions from the guest additions CD. Here is where the fun starts - they don't work on Ubuntu 10.10! Luckily, the unixmen website explains how to fix it - see this article explaining how to install the guest additions.
Note: you may need to upgrade the version of your Virtualbox after installing the guest additions as described in the above article.

Reference:

• A guide on hubpages about How to upgrade ubuntu offline.
• This thread in the Ubuntu forums - solved the problem with the ubuntu-desktop package.
• LifeHacker and Unixmen - for helping me solve the guest additions issue
• The official Ubuntu website
• Google (Used it a lot)

*Update: You will need to run the update manager again - System->Administration->Update Manager. If it complains about some partial upgrade, click the button that says to complete the partial upgrade.