How to upgrade from 16.10 to 18.04

Question

I am unable to upgrade to 18.04 with the following error message

Can not upgrade

An upgrade from 'yakkety' to 'bionic' is not supported with this tool.

How do I solve this?

Answer 1

I did this:

1. backup the entire disk using Clonezilla just in case
2. backup /etc/apt/sources.list
3. edit it as prompted here: How to install software or upgrade from an old unsupported release?

4. that page also states to:

   sudo apt-get update && sudo apt-get dist-upgrade  
   

   but I did:

   sudo apt-get update  
   sudo apt-get upgrade  
   

5. I restored sources.list and replaced yaketty with bionic

6. I tried to update with the GUI tool but at this point something was failing due to the fact that my /etc/fstab didn´t include for some unknown reason an entry for mounting /. I corrected it and rebooted
7. After that the upgrade tool ran smoothly

Answer 2

Ubuntu 16.04 LTS will release-ugprade direct to 18.04 LTS (ie. LTS to next LTS).

Ubuntu 16.10 release-upgraded to Ubuntu 17.04, then to Ubuntu 17.10 (both now EOL) and then to 18.04 LTS. ie. the only tested and supported non-LTS upgrade-path is via every release (not skipping releases). If you want to release-upgrade less often, use a LTS or long-term-support release next time.

The only supported way is via install; I would use 'something-else' & use existing partitions without format. It'll take note of your added packages, wipe system directories then install, add-back your additional programs (if from Ubuntu repos) without touching user data. It's what I'd do.

Please note backup any data before you do the re-install. Better safe than sorry

Answer 3

Please backup all the files you have before trying to upgrade.

Step 1:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
sudo apt install update-manager-core

Step 2:

Change "Prompt" value typing:

sudo vi /etc/update-manager/release-upgrades

Edit "Prompt= ", fill with "lts", so Prompt=lts. To ensure that we will upgrade to the latest version of Ubuntu LTS. And for now the latest LTS version is 18.04.

Step 3:

sudo do-release-upgrade

If any messages say no New release not found, type this command:

sudo do-release-upgrade -d

Please wait for the installation to complete. If there is a Y/N dialogue, please read carefully.