I upgraded to Ubuntu 11.04, Natty Narwhal, from Ubuntu 10.10, Maverick Meerkat, two nights ago. This can be done directly from Maverick Meerkat by going to System->Administration->Update Manager, but before you do that, you should be aware of a couple of things so you don't get frustrated.
First, the time it takes to do the upgrade. This is highly dependent on how fast your Internet connection is and whether the Ubunutu download sites are overloaded. I have a fairly fast connection of about 20Mbps, however I downloaded on April 28th, the day Natty Narwhal was released. I started the upgrade process at 7:50 pm and Natty Narwhal came up and running at 1:07 am. So the first thing you should be aware of is the upgrade can easily take over 5 hours. I actually got all the data down at 12:16. It then took another 51 minutes to finish the install.
What takes so long? Well, all the files for the new version have to be downloaded. There are 1,653 files to download, consisting of the new Unity Desktop and the new LibreOffice, which comes to about 1 Gb of data. You'll need at least that much disk space to do the upgrade.
One thing to ignore is the estimated time to completion that seems to change with each file downloaded. At one point, it estimated that it would take 14 days and 20 hours to complete the upgrade. Since the "Cancel" button is right next to that message, it was mighty tempting to say the heck with it, but I persisted and the next message said 4 hours. I don't know why they even bothered to put the estimated time, just ignore it.
The Upgrade window for the upgrade does a good job of letting you know what's going on in the overall process by walking you through a vertical list of menu choices. The choices were:
Preparing to Upgrade
Setting New Software Channels
Getting New Packages
Installing the Upgrades
Restarting the Computer
Seems simple enough and for the most part it was, just time consumming.
Some things to be aware of. When you first confirm that you want to do the upgrade a scare message comes up saying something to the effect that packages will be added and removed, and that this is a one way process, you can not go back, do you want to proceed. Although my upgrade went flawlessly, I would recommend, as always, to back up your data before doing the upgrade.
As mentioned above, the time consumming part was "Getting New Packages." Cleaning up the system consists of removing 31 packages.
When you restart the system, the first time the computer restarts will take a little bit of time as the new packages are loaded up, but it's not too long. After the initial install, you'll find your boot times are faster.
You will come up in the Unity Desktop that we've heard so much about. This takes getting use to and figuring out. Some quick hints, to shut the system down, go to the upper right menu, like you did with the Gnome desktop in the last release.
What distinguishes the Unity Desktop from the Gnome desktop is the vertical icons along the left side of the screen. You can scroll down these icons to find all your favorite applications. Click on an icon and your application will start. In case you don't like this, your desktop icons are still there. Also there is a laucher application if you click on the upper left Ubuntu icon. This will alow you to quickly search for any application on your sytem. What's missing is the bottom status bar, which allows for more vertical space for browsers and searching the web.
The Unity desktops takes some getting use to, and I'll talk about that in another post.