why do we use systemd?

[Garry T. Williams]

On 7-5-14 13:08:07 vendor wrote:
> Unfortunately, the metric for "clear explanation" is not "number of
> pages."   (Insert obligatory derogatory humor about government
> bureaucracy here.)

Strangely you are replying to someone else, but quoting my message.
So I'll comment.

I never mentioned number of pages in my message.  If you examine the
documentation, you will see that it is very extensive and of the
highest quality.

Over the life of the systemd project, many tools have been developed
to provide the "building blocks for an OS" by those developers.
Hence, the documentation has grown enormously.  It is well-organized
and well-indexed to form a high-quality reference.

Also, in my message, which you quoted:

>> Also (among many others):
>>
>>     http://0pointer.de/blog/projects/systemd.html 
>>     http://0pointer.de/blog/projects/systemd-for-admins-1.html 

That first reference has one of the clearest explanations of systemd
that exists.  When I read that document right after it was posted
originally, I found it very easy to understand and very well-
organized.

In particular, Patrick O'Callaghan lamented:

On 7-5-14 14:30:39 Patrick O'Callaghan wrote:
> +1. One of my pet gripes about systemd is that it introduces a lot
> of new terminology without a clear explanation. I still don't
> understand the difference between a target and a service.

Well, that very first posting by Lennart clearly explains, after
discussing the motivation for systemd:

    1.  service: these are the most obvious kind of unit: daemons that
    can be started, stopped, restarted, reloaded.

    ...

    6.  target: this unit type is used for logical grouping of units:
    instead of actually doing anything by itself it simply references
    other units, which thereby can be controlled together. Examples
    for this are: multi-user.target, which is a target that basically
    plays the role of run-level 5 on classic SysV system, or
    bluetooth.target which is requested as soon as a bluetooth dongle
    becomes available and which simply pulls in bluetooth related
    services that otherwise would not need to be started: bluetoothd
    and obexd and suchlike.

I fail to see where the complaints about the systemd documentation
come from.  Actually reading the documentation makes all these
complaining comments moot.

-- 
Garry T. Williams