Upgrading Ubuntu from 10.04 to 10.10 with a local mirror

I upgraded from Ubuntu 10.04 to Ubuntu 10.10 on my desktop today, using Update Manager. Since 10.04 is a Long Term Support release which features a long period of stability (bug fixes and security fixes only), 10.10 is not automatically offered. I had to hit the Settings button in Update Manager to bring up the Software Sources dialog, then the Updates tab and select "Normal releases" from the Show new distribution releases: drop-down menu in order to get the 10.10 upgrade to show up.

Connecting to a mirror

I wanted to connect to a local Ubuntu archive mirror for the update, since the upgrade would require downloading a large number of packages. There is a large official mirror list at https://launchpad.net/ubuntu/+archivemirrors. To find the repository address for a mirror, click "http" next to its name in this list, then browse to "dists" inside the directory it shows you. Copy the entire resulting URL from the browser's location bar:

http://your.mirror.hostedby.edu/ubuntu/dists

To construct the full repository address for Update manager, add "deb" with a space at the front, and your current Ubuntu version's codename after a space at the end, like this:

deb http://your.mirror.hostedby.edu/ubuntu/dists/ lucid

To enable this mirror, I clicked the "Add" button on the Other Software tab in Software Sources, then pasted in the full address as above. After that, the new mirror was recognized as an main source and I found it on the "Ubuntu Software" tab, in the "Download from" menu. 

Side note: If you have ever added a package mirror the old way, via APT's "sources.list" file, you'll be happy to know that this method fills out that same sources.list with all necessary permutations of the new mirror address, including all the extra repositories like universe or non-free which you'd already enabled elsewhere. It's just much easier to use the Update Manager to handle this now. 

The actual upgrade

Events of note which resulted during and after the upgrade:

• The download of 10.10 from my local mirror took a little over 30 minutes for 1800 packages, which was nice. The config stage took close to an hour after that, with minimal interruptions from Update Manager asking how to proceed.
• Possibly the most exciting thing that happened: A scary, pixelated distorted warning "LOADING CRASH KERNEL" appeared mid screen off center, in early boot stage, but everything was in fact OK after that. Oh well.
• During the upgrade, Update Manager asked if I wanted to keep my customized Apache configuration files and I told it "yes."
• Also during the upgrade, Ardour was removed (I'm not sure why, I do have Ubuntu Studio repositories enabled) and I'll have to look into reinstalling it. This was mentioned by Update Manager, with a warning about the upgrade removing  a bunch of other packages, none of which i cared about.
• Upon first login to 10.10, my desktop background had disappeared. Oops.
• Font anti-aliasing is noticeably better, as if the "sub-pixel smoothing" algorithm in Appearance > Fonts was improved.
• My Intel 5 Series/3400 Series on-board microphone input started working correctly for the first time (Didn't work in 10.04.) 

My custom desktop theme is unchanged, save for those smoother looking fonts. The ATI Fire GL driver installed via Administration > Hardware Drivers (renamed "Additional Drivers" in 10.10) hums along as always.

Working out a few bugs

A few seconds on Google led me to this thread about desktop pictures disappearing on 10.10 upgrade, and indeed, like the folks on the thread I'm running Ubuntu Tweak and had disabled desktop icons prior to the upgrade. So this is an Ubuntu Tweak problem, really. I next went into Tweak's desktop settings, checked "Show desktop icons", and my old wallpaper (and icons) came back. I then unchecked it again and my icons vanished, wallpaper remained. Perfect!

The boot splash problem was a little trickier to track down, but eventually I found this: http://ubuntuforums.org/showthread.php?t=1587411. The solution mentioned here involves a long and involved process of modifying GRUB bootloader files, apparently because the installer didn't set them up right. This isn't really acceptable for the average user, and I wouldn't really mind doing it myself, except that it's 2011 and I expect better from my Linux desktop. There is also a script to run the solution, which doesn't mention that it relies on a non-standard package to be installed, "hwinfo". I haven't run this yet either.

I wanted to check to be sure that this problem was on its way to being solved the right way, so I followed a link from the blog page discussion which sent me to the official bug report on Launchpad, and I have cast my vote for "this bug affects me" (almost 140 such votes on Launchpad!) I also hit the "subscribe" link on the right side of the screen to get emails when the bug changes status. I view participation in this process as even more important than having it working "perfectly" for just me, because it helps fix the problem for everyone.

Outcome

Two big wins with fonts and microphone add up to a good upgrade!

Still strongly considering upgrading directly to 11.04 from here, as the 10.10 upgrade was somewhat lacking in excitement. I figure an alpha release with a new desktop environment might provide that...