On Sun, 10 Dec 2023 02:41:16 +0000
Alexandros Prekates via Dng <dng@???> wrote:

>
> If Linux is multiuser why we tend to run services before even
> users are logged in? How does that makes sense ? Do we assume that
> the real user is the root ? That s(h)e can initiate daemons as s(h)e
> wishes before even s(h)e (the root) logs in ? So the kernel calls
> init which is in essence root-init which is in deeper essence a
> certain user that has more control on the machine ? So the kernel
> by defaults 'logins' a certain user and runs his-her init . So
> is that multiuser or singleuser ? That root-init can make the
> machine from a general purpose one to a doom game server.

Hi,
it is like this for the same reason that your car
has 4 wheels but not 4 independent steering
wheels. Think about a system where one user wants
his init to boot the system and another user
instead to shut it down, the third user wants
all network ports open and the forth all closed
...etc...
So for a better working of the system there needs
to be some superior instance that keeps it
in a coherent state and cleans up the mess
caused by the user(s) slowing the inevitable
increase of chaos over time that will in the end
lead to the reboot of the box (so to say
the death and rebirth of it).

>
> So if init is userFoo's init then how Linux is multiuser ?

...in that more than one user could use it simultaneously to
a certain extent?

> Dont other users are entitled to have their inits ?

... of course yes if they have their own box or virtual machines.

> Or do we have in mind restricted users or a certain category
> of user lacking certain skill-sets. In which case we should

e.g. users that do the foreseen work, nothing more and
nothing less.

> call Linux multi-word-editors or multi-image-editors system ?
> Or should we assume that a mail server IS the machine?

the little chinese backdoor hidden in the motherboard is "The Machine"...

> But in that case is not multiuser. And why you would need a multiuser
> system if you want to setup a computer as a certain server you like
> excluding other users and their cases.

For security reasons?

> Could it be that semantics from differents origins and use cases
> from other origins have been mixed up here blurring our thoughts
> in these matters?

...indeed

> Or maybe userFoo should not use root-init for his(her) wishes
> and root-init should belong to Atlas (1) Meaning the cyber-god-sysadm
> entrusted with the job to hold the userland ! (2) . Which in deeper
> meaning possible means Atlas-init should init and supevise daemons
> that keep the machine+OS stable and running and ONLY those . And if
> Atlas wanted to try to live in userland to fire up a webserver he
> should setup his own sisyphos-init like every commoner .
>
> Could it be that Corbato had not in mind (3) that in a multiuser system
> a certain user could fire up his daemons first of all the others and
> practically turn it into a single user system ?

Today he (the user, a person) could have his own vm
to play "President" at will. Trying to play "President"
all together on the same box, vm, nation, house
in the history of mankind didn't work out so far
and has been rather a troublesome process
which is still ongoing and that will end only
when all entities involved will be enlightened
thus automatically wanting the same "True Right Thing"
at the same point in time. We are not there yet...

> Any why in 1979's Unix init is not envisioned as a general
> service-daemons supervisor but:
>     init is invoked as the last step of the
>     boot procedure (see boot(8)). Generally its role is to create a pro-
>     cess for each typewriter on which a user may log in.(4)

>
> So could it be that by various twists of fate and circumstances (pc
> dissimination) init was given a secondary role that wasnt never
> indended to carry ? A role that broke its original semantics intentions
> bestowed upon it by non-PC compu-techies ?

Could this be called evolution?

> (1) https://en.wikipedia.org/wiki/Atlas_(mythology)
> (2) https://www.youtube.com/watch?v=Nn-SGblUhi4   (2:00)
> (3) https://www.youtube.com/watch?v=Q07PhW5sCEk
> (4) PDF and PostScript Renditions of Seventh Edition Manual
>     https://plan9.io/7thEdMan/bswv7.html

>
> Alexandros.

Ciao,
Tito