A system without systemd?

[Ralf Mardorf]

On Thu, 18 Nov 2021 09:18:25 -0600, Keith wrote:
>On 11/17/21 12:08 AM, Ralf Mardorf via ubuntu-users wrote:
>> On Tue, 16 Nov 2021 20:12:24 -0600, Keith wrote:  
>>> Can you live without the following software packages
>>> installed, or not working on your system?  
>>
>> This list of packages is irrelevant. The essential package "init" for
>> example is listed, but it doesn't contain something that is
>> important, even not the init link against whatsoever, but the
>> package "udev" isn't listed, while it is essential with or without
>> being a direct dependency. While one or the other dependency could
>> be satisfied by another init system and probably faking that systemd
>> is installed by e.g. an empty dummy package, other essential
>> software might need a fork, for example see
>> https://wiki.gentoo.org/wiki/Project:Eudev .
>>
>> However, the output of "sudo apt -s purge systemd" is moot.
>>  
>
>You do know what the word "essential" means, right?
>
>But, go ahead and try the command without the "-s" option and then hit
>Y where prompted. See what happens.

Replacing an init system, is not the same as removing an init system.
You are showing what happens by removing the init system.

"File list of package init in impish of architecture amd64

/usr/share/doc/init/changelog.gz
/usr/share/doc/init/copyright"

- https://packages.ubuntu.com/impish/amd64/init/filelist

The dependencies are against an init system, the OP wants to replace by
another init system.

However, the OP even doesn't need to change this package at all, the OP
"just" needs to replace all systemd related packages by empty dummy
packages, to fulfil package dependencies from official repositories and
also to install another init system.

Now there are mostly two remaining issues. Packages probably provide
systemd units and no init script files anymore, so the OP needs to
write all those files. The OP needs to integrate a new device manager,
the default udev (one of the systemd related packages) can't be used
anymore. There are a few other issues, however, your purge the init
system, instead of replacing it is moot.