For how long can I wait to do a release-upgrade on Server 18.04.6 LTS?

[Keith]

On 4/15/22 10:31 AM, Bo Berglund wrote:
> I have an Ubuntu 18.04.6 LTS server running inside a VMWare Esx virtualization
> server. It is located across the ocean from where I live and I am only able to
> use SSH (through PuTTY) to access it for maintenance.
> This is done via a OpenVPN connection into the LAN it lives on.
>
> The Ubuntu was release-upgraded a number of years back from 16.04, which I
> believe was first installed on Feb 18 2018 (before 18.04 was released).
> (At least that is the date of the files in /var/log/installer/)
>
> So now when I log on I am getting the nag message (only when it is fully
> upgraded on 18.04):
>
> New release '20.04.4 LTS' available.
> Run 'do-release-upgrade' to upgrade to it.
>
> I would have done this upgrade 2 years ago if I had not been prohibited to
> travel to the main office in Texas due to Covid-19....
>
> Now there is soon an official new release 22.04, and I have yet not been able to
> schedule a visit...
>
> Questions:
>
> 1) Will it be possible to upgrade from 18.04.6 to 20.04 after 22.04 has been
> released?
>
> 2) If so, is there some mechanism in sudo do-release-upgrade which makes sure
> that it won't grab the 22.04 release rather than the 20.04?
> I think I would not like to risk skipping one release in the upgrade...
>
> IOW:
> Can I wait with the do-release-upgrade without bad issues hunting me when I am
> in fact able to handle the upgrade on location after summer?
>
>

1. Yes
2. By default, a LTS release only upgrades to the next LTS release
available, i.e. 18.04->20.04. Skipping releases during upgrades is not
supported.
3. Yes

End of life for 18.04 is Apr 26, 2023. That's assuming you don't opt to
sign up your server for Extended Security Maintenance (esm). If you do
that, the EOL will be Apr 26, 2028.

If you don't wish to see any further prompts about upgrading to a new
LTS, you can edit /etc/update-manager/release-upgrades and change the
value for "Prompt" to "never".

--
Keith