Can't upgrade Ubuntu 18.04 to 20.04

[readableauthor]

You should remove all PPAs. You can use Software & Updates app for that.

[yancek]

Did you comment out the ppa entries in the /etc/apt/sources.list file? You can do this by putting a # at the beginning of each line with ppa in it as shown below.

# http://ppa.launchpad.net/libreoffice/ppa/ubuntu bionic InRelease

[kubasienczyk]

"An unresolvable error occured while calculating the upgrade".

Not very informative.

[kubasienczyk]

I haven't! Trying that now.

[kubasienczyk]

Same thing again:

After updating your package information, the essential package 'ubuntu-minimal' could not be located. This may be because you have no official mirrors listed in your software sources, or because of excessive load on the mirror you are using. See /etc/apt/sources.list for the current list of configured software sources.
In the case of an overloaded mirror, you may want to try the upgrade again later.

This is my sudo gedit /etc/apt/sources.list:

# deb cdrom:[Ubuntu 18.04.3 LTS _Bionic Beaver_ - Release amd64 (20190805)]/ bionic main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
# deb ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic main restricted
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic main restricted

## Major bug fix updates produced after the final release of the
## distribution.
# deb ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic-updates main restricted
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic-updates main restricted

## 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 ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic universe
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic universe
# deb ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic-updates universe
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic-updates 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 ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic multiverse
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic multiverse
# deb ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic-updates multiverse
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic-updates multiverse

## 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-src http://pl.archive.ubuntu.com/ubuntu/ bionic-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 focal partner
# deb-src http://archive.canonical.com/ubuntu bionic partner

# deb ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic-security main restricted
# deb-src http://security.ubuntu.com/ubuntu bionic-security main restricted
# deb ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic-security universe
# deb-src http://security.ubuntu.com/ubuntu bionic-security universe
# deb ftp://ftp.fu-berlin.de/linux/ubuntu/ bionic-security multiverse
# deb https://dl.winehq.org/wine-builds/ubuntu/ focal main # disabled on upgrade to focal
# deb-src https://dl.winehq.org/wine-builds/ubuntu/ bionic main
# deb-src http://security.ubuntu.com/ubuntu bionic-security multiverse

[Holger_Gehrke]

Most PPAs these days are installed in files of their own in '/etc/apt/sources.list.d/'. The sources you commented out in /etc/apt/sources.list where not PPAs but official sources which might by now have gone offline. There's a page in the Ubuntu Community Wiki which describes the procedure for upgrading an EOL release.

Holger

[atrab101]

I recently posted this thread, to thank the developers and community for a remarkably smooth upgrade from 18.04 to 20.04. https://ubuntuforums.org/images/ubun.../bg_dotted.gif. I am an unusual case, in that I built my system over 7 years ago with the last generation of ASUS motherboard that was XP compatible. My research also showed Linux compatibility. So I have a frozen configuration with spare parts I purchased to insure that I can support my system when obsolete parts are no longer available. The government does something similar when purchasing spare parts for remotely located systems that have no external connectivity, this they can support as a self contained configuration for decades.

So few people (if any!) will do what I am doing, but it is still remarkable to me that Ubuntu is so stable and upgrades have always worked without any problems. My dual boot system gives me great performance on the Ubuntu side, and it preserves 30 years of Windows history on the XP side. I regularly do disk images with Norton Ghost 14 and Acronis True Image on the XP side. I do Disk Images with Clonezilla on the Ubuntu side. All image methodology has been proven with tests, so I know I am protested in the event of system failures.

I caution that upgrades should be done with great care, to follow exact instructions. If in doubt, pause and research. Read about problems on this forum that others have experienced and avoid the same. For example, I believe that if I had removed obsolete packages, my upgrade would have been burdened with searching for the same to address and update them first, but they could not be found because obsolete. Maybe there is a way to overcome this, but it seemed best to me to avoid. I have found no negative consequence to retaining obsolete packages, which of course are just inactive.

Best wishes for your upgrading. Perhaps another attempt would be more successful. Follow the advice of the great people that support these forums.

[atrab101]

Sorry for the bad link. Hopefully this will work:

https://ubuntuforums.org/showthread.php?t=2489725

[kubasienczyk]

So I'm trying to follow the instructions at this link:
https://help.ubuntu.com/community/EOLUpgrades

The crucial part is apparently getting my sources.list in order. As dumb as that question might come across, how do I get from this:

# deb cdrom:[Ubuntu 18.04.3 LTS _Bionic Beaver_ - Release amd64 (20190805)]/ bionic main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://ubuntu.task.gda.pl/ubuntu/ bionic main restricted
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://ubuntu.task.gda.pl/ubuntu/ bionic-updates main restricted
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic-updates main restricted

## 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://ubuntu.task.gda.pl/ubuntu/ bionic universe
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic universe
deb http://ubuntu.task.gda.pl/ubuntu/ bionic-updates universe
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic-updates 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://ubuntu.task.gda.pl/ubuntu/ bionic multiverse
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic multiverse
deb http://ubuntu.task.gda.pl/ubuntu/ bionic-updates multiverse
# deb-src http://pl.archive.ubuntu.com/ubuntu/ bionic-updates multiverse

## 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-src http://pl.archive.ubuntu.com/ubuntu/ bionic-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 bionic partner
# deb-src http://archive.canonical.com/ubuntu bionic partner

deb http://ubuntu.task.gda.pl/ubuntu/ bionic-security main restricted
# deb-src http://security.ubuntu.com/ubuntu bionic-security main restricted
deb http://ubuntu.task.gda.pl/ubuntu/ bionic-security universe
# deb-src http://security.ubuntu.com/ubuntu bionic-security universe
deb http://ubuntu.task.gda.pl/ubuntu/ bionic-security multiverse
deb https://dl.winehq.org/wine-builds/ubuntu/ bionic main
# deb-src https://dl.winehq.org/wine-builds/ubuntu/ bionic main
# deb-src http://security.ubuntu.com/ubuntu bionic-security multiverse

To this:

## EOL upgrade sources.list
# Required
deb http://old-releases.ubuntu.com/ubuntu/ CODENAME main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ CODENAME-updates main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ CODENAME-security main restricted universe multiverse

# Optional
#deb http://old-releases.ubuntu.com/ubuntu/ CODENAME-backports main restricted universe multiverse

I'm having a hard time figuring out what to comment out, comment in - and how. Also, what's the codename? Bionic? Bionic Beaver? bionic-beaver?

Help the brother out. I'm in the dark here.

[readableauthor]

Have you tried Software & Updates app I suggested to remove the PPAs? You shouldn't be using old-releases, it's in general archive under bionic codename