Accessing upgrade to 11.04

You should be able to re-enable checking for release upgrades by clicking the Settings... button in the lower-left corner of the Update Manager window, which brings up the Software Sources window; then click the Updates tab, and at the bottom, change "Show new distribution releases" to "Normal releases".

Alternatively, you can also upgrade to Ubuntu 11.04 using the procedure "for servers" (which works equally well on desktops) at https://help.ubuntu.com/community/NattyUpgrades#Network%20Upgrade%20for%20Ubuntu%20Servers%20(Recommended).

In Update Manager> settings > Update tab there is no "Show new distribution releases" option. It is already set to "Normal releases".
I tried the servers procedure without success. In Terminal, it showed as latest version of update-manager-core already installed, and no new upgrade version available.

This is on a netbook by the way - does that make a difference?

Maybe I should just download to a CD and start again?

What do you mean when you say that there is no "Show new distribution releases" option? (You then say that "It is already set to...", so you don't really mean it's not there, do you?)

When you followed the instructions at https://help.ubuntu.com/community/NattyUpgrades#Network%20Upgrade%20for%20Ubuntu%20Servers%20(Recommended), did you perform step 2?

It's normal for update-manager-core to already be installed. Did you actually run "sudo do-release-upgrade"? If not, please do so--it should be able to upgrade your system to Natty.

If you had run "sudo do-release-upgrade" and that hadn't worked, please open a Terminal window and run this command by copying it and pasting it into the Terminal:

sudo do-release-upgrade; lsb_release -a; cat /etc/update-manager/release-upgrades

(If that command is split into multiple lines in your email, please come to https://answers.launchpad.net/ubuntu/+source/update-manager/+question/156723 to copy it.)

Then select all the text in the Terminal (Edit > Select All), copy it to the clipboard (Edit > Copy), and paste it here.

Apologies - I overlooked that it was a "Show new distribution releases" option - I was looking for that to appear in the drop down box.
It does however show "Normal releases".
I didn't do step 2 because it said the update-manager-core was already installed; also I don't know how to do the "edit /etc/update-manager/release-upgrades and set Prompt=normal" bit - I'm not very good on the technical stuff as you can see!
I did try the "sudo do-release-upgrade" and the "sudo do-release-upgrade; lsb_release -a; cat /etc/update-manager/release-upgrades". This is what I got:
arnold@arnold-laptop:~$ sudo do-release-upgrade
[sudo] password for arnold:
Checking for a new ubuntu release
No new release found
arnold@arnold-laptop:~$ sudo do-release-upgrade; lsb_release -a; cat /etc/update-manager/release-upgrades
sudo: do-release-upgrade: command not found
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.10
Release: 10.10
Codename: maverick
cat: /etc/update-manager: Is a directory
cat: /release-upgrades: No such file or directory
arnold@arnold-laptop:~$

Hope this is helpful.

Are you sure that command wasn't split into multiple lines? It was apparently *not* copied correctly.

Well, it gave some information. So you can just run this command, and post the text from the Terminal (starting with the beginning of the line on which you paste in this command):

sudo do-release-upgrade; cat /etc/update-manager/release-upgrades

Again, if that command is split into multiple lines in your email, please come here to https://answers.launchpad.net/ubuntu/+source/update-manager/+question/156723 to copy it.

This is what I got:

arnold@arnold-laptop:~$ sudo do-release-upgrade; cat /etc/update-manager/release-upgrades
[sudo] password for arnold:
Checking for a new ubuntu release
No new release found
# Default behavior for the release upgrader.

[DEFAULT]
# Default prompting behavior, valid options:
#
# never - Never check for a new release.
# normal - Check to see if a new release is available. If more than one new
# release is found, the release upgrader will attempt to upgrade to
# the release that immediately succeeds the currently-running
# release.
# lts - Check to see if a new LTS release is available. The upgrader
# will attempt to upgrade to the first LTS release available after
# the currently-running one. Note that this option should not be
# used if the currently-running release is not itself an LTS
# release, since in that case the upgrader won't be able to
# determine if a newer release is available.
prompt=normal
arnold@arnold-laptop:~$

Is that helpful?

Helpful, yes. Do I know for sure what's causing the problem? No.

Please run:

cat /etc/apt/sources.list; ls -l /etc/apt/sources.list.d; sudo apt-get update

As before, you might need to come to https://answers.launchpad.net/ubuntu/+source/update-manager/+question/156723 to copy that line effectively. Then select all the text in the Terminal (starting with the line on which you paste that command), copy it to the clipboard, and paste it here.

It's important to paste the results of that command here before running "sudo do-release-upgrade", since sometimes "sudo do-release-upgrade" will clear the Terminal window, rendering previous output uncopyable. But as soon as possible after you've run that command and posted the text associated with it (as requested above), please do run "sudo do-release-upgrade" (without the quotes), select all the text in the Terminal associated with running that command (i.e., starting with the line on which you pasted or typed it in), copy it to the clipboard, and paste it here. It might give the same error message as before ("No new release found"), or it might not. It might even work, successfully upgrading your system to Ubuntu 11.04. Maybe.

On second thought, instead of running that one long command (starting with "cat"), please run these five commands separately:

cat /etc/apt/sources.list
ls -l /etc/apt/sources.list.d
sudo apt-get update
sudo apt-get -y upgrade
sudo apt-get -y dist-upgrade

Those commands will *not* upgrade your system to a newer release (Ubuntu 11.04), though they may upgrade the packages on it to the latest available in your current release (Ubuntu 10.10). After running those commands and copying the text from the Terminal window and posting it here, please still run "sudo do-release-upgrade" and see if it works (and if it doesn't, copy the text from the Terminal associated with that most recent run of "sudo do-release-upgrade" and post it here).

Here it is:

arnold@arnold-laptop:~$ cat /etc/apt/sources.list
# deb cdrom:[Ubuntu-Netbook-Remix 9.10 _Karmic Koala_ - Release i386 (20091028.4)]/ karmic main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://gb.archive.ubuntu.com/ubuntu/ maverick main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ maverick main

## Major bug fix updates produced after the final release of the
## distribution.

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ maverick universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ maverick universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://gb.archive.ubuntu.com/ubuntu/ maverick multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ maverick multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://gb.archive.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse
# deb-src http://gb.archive.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu maverick partner
# deb-src http://archive.canonical.com/ubuntu karmic partner

deb http://security.ubuntu.com/ubuntu/ maverick-security restricted main multiverse universe
deb http://gb.archive.ubuntu.com/ubuntu/ maverick-updates restricted main multiverse universe
deb http://extras.ubuntu.com/ubuntu maverick main #Third party developers repository
arnold@arnold-laptop:~$ ls -l /etc/apt/sources.list.d
total 0
arnold@arnold-laptop:~$ sudo apt-get update
[sudo] password for arnold:
Get:1 http://archive.canonical.com maverick Release.gpg [198B]
Ign http://archive.canonical.com/ubuntu/ maverick/partner Translation-en
Ign http://archive.canonical.com/ubuntu/ maverick/partner Translation-en_GB
Get:2 http://archive.canonical.com maverick Release [5,925B]
Get:3 http://extras.ubuntu.com maverick Release.gpg [72B]
Ign http://extras.ubuntu.com/ubuntu/ maverick/main Translation-en
Ign http://extras.ubuntu.com/ubuntu/ maverick/main Translation-en_GB
Hit http://gb.archive.ubuntu.com maverick Release.gpg
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/main Translation-en
Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/main Translation-en_GB
Hit http://security.ubuntu.com maverick-security Release.gpg
Ign http://security.ubuntu.com/ubuntu/ maverick-security/main Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/main Translation-en_GB
Hit http://extras.ubuntu.com maverick Release
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/multiverse Translation-en
Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/multiverse Translation-en_GB
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/restricted Translation-en
Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/restricted Translation-en_GB
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/universe Translation-en
Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/universe Translation-en_GB
Hit http://gb.archive.ubuntu.com maverick-updates Release.gpg
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/main Translation-en
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/main Translation-en_GB
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/multiverse Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/multiverse Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/multiverse Translation-en_GB
Ign http://security.ubuntu.com/ubuntu/ maverick-security/restricted Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/restricted Translation-en_GB
Ign http://security.ubuntu.com/ubuntu/ maverick-security/universe Translation-en
Ign http://security.ubuntu.com/ubuntu/ maverick-security/universe Translation-en_GB
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/multiverse Translation-en_GB
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/restricted Translation-en
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/restricted Translation-en_GB
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/universe Translation-en
Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/universe Translation-en_GB
Hit http://gb.archive.ubuntu.com maverick Release
Hit http://security.ubuntu.com maverick-security Release
Hit http://gb.archive.ubuntu.com maverick-updates Release
Get:4 http://archive.canonical.com maverick/partner i386 Packages [7,781B]
Hit http://extras.ubuntu.com maverick/main i386 Packages
Hit http://gb.archive.ubuntu.com maverick/main Sources
Hit http://security.ubuntu.com maverick-security/restricted i386 Packages
Hit http://security.ubuntu.com maverick-security/main i386 Packages
Hit http://security.ubuntu.com maverick-security/multiverse i386 Packages
Hit http://security.ubuntu.com maverick-security/universe i386 Packages
Hit http://gb.archive.ubuntu.com maverick/universe Sources
Hit http://gb.archive.ubuntu.com maverick/multiverse Sources
Hit http://gb.archive.ubuntu.com maverick/main i386 Packages
Hit http://gb.archive.ubuntu.com maverick/restricted i386 Packages
Hit http://gb.archive.ubuntu.com maverick/universe i386 Packages
Hit http://gb.archive.ubuntu.com maverick/multiverse i386 Packages
Hit http://gb.archive.ubuntu.com maverick-updates/restricted i386 Packages
Hit http://gb.archive.ubuntu.com maverick-updates/main i386 Packages
Hit http://gb.archive.ubuntu.com maverick-updates/multiverse i386 Packages
Hit http://gb.archive.ubuntu.com maverick-updates/universe i386 Packages
Fetched 14.0kB in 1s (13.1kB/s)
Reading package lists... Done
arnold@arnold-laptop:~$ sudo apt-get -y upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
arnold@arnold-laptop:~$ sudo apt-get -y dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
arnold@arnold-laptop:~$

It didn't work. Got this text:

arnold@arnold-laptop:~$ sudo do-release-upgrade
Checking for a new ubuntu release
No new release found
arnold@arnold-laptop:~$

Sorry to be causing this problem - I appreciate your help.

Before we proceed further, there is a correction you should make to your /etc/apt/sources.list file, to avoid problems later. This is *not* causing problems now (and in particular, is *not* the cause of your current problem), but it might cause problems later, if you ever want to use anything from the backports repository, or source packages from the partner repository.

I recommend you first back up the file:

sudo cp /etc/apt/sources.list /etc/apt/sources.list.old

Then open it up in a text editor as root, so you can modify it. One way to do that is to press Alt+F2, type/paste in

gksu gedit /etc/apt/sources.list

and press enter.

Once you're in the text editor, change the three remaining instances of "karmic" to "maverick" (excluding the two instances at the very top of the file, which you needn't change).

(Once you get your system upgraded to Ubuntu 11.04, that *should* be changed automatically from "maverick" to "natty", but you shouldn't make that change now.)

I'll post again soon with instructions for continuing to work on the the problem upgrading. But I recommend making this change first.

Back to working on the problem at hand:

Maybe there is a problem with the mirror you're using. Perform Step 1 of https://help.ubuntu.com/community/PackageManagerTroubleshootingProcedure, then quit the Update Manager and run:

sudo apt-get update
sudo apt-get -y upgrade
sudo apt-get -y dist-upgrade

Post the output here, as before (or save it, so you can post it later), then try running "sudo do-release-upgrade" and see if it works this time.

"Sorry to be causing this problem - I appreciate your help."

There is no need to apologize--seeking and receiving help (and providing it) is what this forum is for.

It still didn't work. I'm hoping I did everything correctly!
This is what I got:

arnold@arnold-laptop:~$ sudo apt-get update

Hit http://extras.ubuntu.com maverick Release.gpg

Ign http://extras.ubuntu.com/ubuntu/ maverick/main Translation-en

Hit http://archive.canonical.com maverick Release.gpg

Ign http://archive.canonical.com/ubuntu/ maverick/partner Translation-en

Hit http://security.ubuntu.com maverick-security Release.gpg

Ign http://security.ubuntu.com/ubuntu/ maverick-security/main Translation-en

Ign http://security.ubuntu.com/ubuntu/ maverick-security/main Translation-en_GB

Hit http://gb.archive.ubuntu.com maverick Release.gpg

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/main Translation-en

Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/main Translation-en_GB

Ign http://extras.ubuntu.com/ubuntu/ maverick/main Translation-en_GB

Hit http://extras.ubuntu.com maverick Release

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/multiverse Translation-en

Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/multiverse Translation-en_GB

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/restricted Translation-en

Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/restricted Translation-en_GB

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick/universe Translation-en

Hit http://gb.archive.ubuntu.com/ubuntu/ maverick/universe Translation-en_GB

Hit http://gb.archive.ubuntu.com maverick-updates Release.gpg

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/main Translation-en

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/main Translation-en_GB

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/multiverse Translation-en

Ign http://archive.canonical.com/ubuntu/ maverick/partner Translation-en_GB

Hit http://archive.canonical.com maverick Release

Ign http://security.ubuntu.com/ubuntu/ maverick-security/multiverse Translation-en

Ign http://security.ubuntu.com/ubuntu/ maverick-security/multiverse Translation-en_GB

Ign http://security.ubuntu.com/ubuntu/ maverick-security/restricted Translation-en

Ign http://security.ubuntu.com/ubuntu/ maverick-security/restricted Translation-en_GB

Ign http://security.ubuntu.com/ubuntu/ maverick-security/universe Translation-en

Ign http://security.ubuntu.com/ubuntu/ maverick-security/universe Translation-en_GB

Hit http://security.ubuntu.com maverick-security Release

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/multiverse Translation-en_GB

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/restricted Translation-en

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/restricted Translation-en_GB

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/universe Translation-en

Ign http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/universe Translation-en_GB

Hit http://gb.archive.ubuntu.com maverick Release

Hit http://gb.archive.ubuntu.com maverick-updates Release

Hit http://extras.ubuntu.com maverick/main i386 Packages

Hit http://archive.canonical.com maverick/partner i386 Packages

Hit http://security.ubuntu.com maverick-security/restricted i386 Packages

Hit http://security.ubuntu.com maverick-security/main i386 Packages

Hit http://security.ubuntu.com maverick-security/multiverse i386 Packages

Hit http://security.ubuntu.com maverick-security/universe i386 Packages

Hit http://gb.archive.ubuntu.com maverick/main Sources

Hit http://gb.archive.ubuntu.com maverick/universe Sources

Hit http://gb.archive.ubuntu.com maverick/multiverse Sources

Hit http://gb.archive.ubuntu.com maverick/main i386 Packages

Hit http://gb.archive.ubuntu.com maverick/restricted i386 Packages

Hit http://gb.archive.ubuntu.com maverick/universe i386 Packages

Hit http://gb.archive.ubuntu.com maverick/multiverse i386 Packages

Hit http://gb.archive.ubuntu.com maverick-updates/restricted i386 Packages

Hit http://gb.archive.ubuntu.com maverick-updates/main i386 Packages

Hit http://gb.archive.ubuntu.com maverick-updates/multiverse i386 Packages

Hit http://gb.archive.ubuntu.com maverick-updates/universe i386 Packages

Reading package lists... Done

arnold@arnold-laptop:~$ sudo apt-get -y upgrade

Reading package lists... Done

Building dependency tree

Reading state information... Done

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

arnold@arnold-laptop:~$ sudo apt-get -y dist-upgrade

Reading package lists... Done

Building dependency tree

Reading state information... Done

Calculating upgrade... Done

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

arnold@arnold-laptop:~$

arnold@arnold-laptop:~$ sudo do-release-upgrade

Checking for a new ubuntu release

No new release found

arnold@arnold-laptop:~$

It does not appear that step 1 of that procedure was performed successfully. That doesn't necessarily mean you did something wrong--it could have failed to apply the settings correctly, due to some bug. In any case, however, it seems to still be using the regional servers, rather than the central servers. Let's check and see if the changes you attempted to make in step 1 of that procedure were successful. Please run this command, and post all the text from the Terminal (starting with the line where you paste in this command):

cat /etc/apt/sources.list

You will notice that you've run this before. That's OK. Whether or not what you see looks like what you saw before, please paste it into your post.

This is what I got:
arnold@arnold-laptop:~$ cat /etc/apt/sources.list
# deb cdrom:[Ubuntu-Netbook-Remix 9.10 _Karmic Koala_ - Release i386 (20091028.4)]/ karmic main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://gb.archive.ubuntu.com/ubuntu/ maverick main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ maverick main

## Major bug fix updates produced after the final release of the
## distribution.

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ maverick universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ maverick universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://gb.archive.ubuntu.com/ubuntu/ maverick multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ maverick multiverse

## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://gb.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse
# deb-src http://gb.archive.ubuntu.com/ubuntu/ maverick-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu maverick partner
# deb-src http://archive.canonical.com/ubuntu maverick partner

deb http://security.ubuntu.com/ubuntu/ maverick-security restricted main multiverse universe
deb http://gb.archive.ubuntu.com/ubuntu/ maverick-updates restricted main multiverse universe
deb http://extras.ubuntu.com/ubuntu maverick main #Third party developers repository
arnold@arnold-laptop:~$

Following step 1 of https://help.ubuntu.com/community/PackageManagerTroubleshootingProcedure is supposed to have the effect of replacing each instance of http://gb.archive.ubuntu.com/ubuntu (or whatever mirror URL you have) with http://archive.ubuntu.com/ubuntu in /etc/apt/sources.list. But for some reason, it appears not to be working for some users. When you followed those instructions, did you actually select the main server, or did you just open up the Software Sources window but not actually make any change? (That seems to me like the mistake some users might be making.)

I just opened up Update Manager, selected "Settings" and left it open
whilst doing the terminal stuff. I don't know how to select the main
server from there.

BUT ...

when I started my netbook today, Update Manager opened and gave me the
option to upgrade to 11.04 - which I accepted! The upgrade is now in
progress and if it is successful I will close my question on Launchpad.
Do you think it was a result of the changes we have made, or is there an
automatic fresh opportunity to upgrade after a set period?
Whatever, I am grateful for your help and support.

David Yarwood

On Mon, 2011-05-16 at 19:56 +0000, Eliah Kagan wrote:
> Your question #156723 on update-manager in Ubuntu changed:
> https://answers.launchpad.net/ubuntu/+source/update-manager/+question/156723
>
> Status: Open => Needs information
>
> Eliah Kagan requested more information:
> Following step 1 of
> https://help.ubuntu.com/community/PackageManagerTroubleshootingProcedure
> is supposed to have the effect of replacing each instance of
> http://gb.archive.ubuntu.com/ubuntu (or whatever mirror URL you have)
> with http://archive.ubuntu.com/ubuntu in /etc/apt/sources.list. But for
> some reason, it appears not to be working for some users. When you
> followed those instructions, did you actually select the main server, or
> did you just open up the Software Sources window but not actually make
> any change? (That seems to me like the mistake some users might be
> making.)
>

It is not sufficient merely to open the Software Sources window. In fact, it should *not* ever be open when attempting to perform package management operations from the command-line.

You have to actually change the server. This is in the Ubuntu Software tab. There is a drop-down menu labeled "Download from:". See http://technologytales.com/wp-content/uploads/2009/06/Screenshot-Software-Sources.png.

Anyway, I guess that's moot now, because...

> when I started my netbook today, Update Manager opened and gave
> me the option to upgrade to 11.04 - which I accepted!

Well, cool!

> Do you think it was a result of the changes we have made, or is there
> an automatic fresh opportunity to upgrade after a set period?

Whenever there's a newer stable release than the one you're running, you should always be able to upgrade to in the Update Manager (or by upgrading all the packages on your system to their latest versions in your current release, and then running "sudo do-release-upgrade") it so long as Prompt=normal in /etc/update-manager/release-upgrades (i.e, so long as "Show new distribution releases" is set to "Normal releases" in Software Sources).

So, there is no automatic fresh opportunity, because the opportunity is never supposed to go away.

As for whether or not it was the result of changes we made...I'm not sure. Do your recall when during this process the most recent time was that you ran the Update Manager and were *not* provided with the ability to upgrade?

I suppose the last time I opened Update Manager was when you asked me to do it to change the server, but I didn't change anything, just left it open as I said.
Anyway, the upgrade seems to have happened successfully though I did happen to notice at one point during the "clean-up" that a line appeared in Terminal which said something like "failed to read mirror file". You said something on 13/05 about a mirror? I have no idea what a mirror is in this context. Do I need to do anything now or will the fresh installation have resolved any inherent problem?

The output of "lsb_release -d" was 11.04, so all seems OK.
Thanks again for the help.