Do I need avahi?

[lee]

Marko Vojinovic <vvmarko at gmail.com> writes:

> On Sun, 28 Jul 2013 17:03:29 +0200
> lee <lee at yun.yagibdah.de> wrote:
>> Tim <ignored_mailbox at yahoo.com.au> writes:
>> > They might not *actually* need it.  i.e. They *may* make use of it
>> > for some features, that you *might* use, so they require it for
>> > those purposes.  But if you don't use those features, it doesn't
>> > need to be running.
>> 
>> Then why don't packages that don't depend on others but might use them
>> simply suggest those packages rather than require them?
>
> What is the actual difference?

The difference is that not a huge number of unneeded packages needs to
be installed, wasting resources, and that unneeded packages can be
removed without bringing down more or less the whole system which
doesn't need the unneeded package in the first place.

> If package A needs package B in order to provide some functionality,
> then it needs it.

Package B doesn't need to and shouldn't be installed when the particular
functionality A can provide when B is installed is not needed.

I don't need avahi.  It's disabled and now even masked, and I'm not
missing any functionality.  I want to remove the package, but stupidly
handled dependencies prevent me from removing it.

Not being able to remove obsolete packages is a bug.

> Otherwise, it doesn't. Providing package A without B
> as a dependency will lead to A having less functionality than it is
> supposed to have, and that is a bug.

It cannot be a bug when a package doesn't have functionality the user
doesn't want.  It is not supposed to have unwanted functionality.

> The fact that you might not use or need this functionality doesn't
> enter the equation, since someone else might try to use it, only to
> find out that it doesn't work --- which would be a clear bug.

Someone who needs it would simply look at the suggested packages, see
which one enables the needed functionality and install it.

> So there is no sharp distinction between the dependencies that would
> render a package semi-functional versus non-functional. It either works
> fully or it doesn't.

The packages I have installed are fully functional for me without avahi.

> OTOH, the most famous exception from this design are the multimedia
> codecs, but that is just due to legal complications rather than a
> design choice.

When you look at the plugins for nautlius and thunar, you'll find
another example.

> Nevertheless, I have seen various proposals for RPM to include the
> concept of soft dependencies. But AFAIK, it hasn't happened so far.

RPM doesn't support suggested packages?  Are you serious?

>> When a service is
>> disabled, the service should be *disabled* in the sense that it is
>> turned off because that's what it usually means.
>
> I suggest that you read this:
>
>    http://0pointer.de/blog/projects/three-levels-of-off
>
> It explains the differences between "stop", "disable" and "mask". Also,
> note that it is just a tad bit outdated, since today you can just say
>
>   systemctl mask someservice
>
> rather than making links manually. But the essence is the same.

I've seen it in man systemctl.  The wording they are using is
misleading.

>> Having hundreds or thousands of packages installed that aren't needed
>> is not only annoying and a big waste of resources --- everyone needs
>> the disk space for them, and it will take bandwidth and time when the
>> packages are updated and downloaded by everyone --- it's also a
>> security risk.
>
> If you find disk space precious, I suggest that you choose the minimal
> install option in anaconda,

There is such an option?  So far, I've only used the default life image
from the Fedora website, and when you boot it, you get a working system
and an installer you can start.  That installer doesn't allow you to
make any choices about what to install.  How do make choices about what
to install before installing?

> and after the installation tweak the system to your needs manually via
> yum. That way you will have a very clean system, containing only the
> stuff you actually need to use, give or take...

Well, how do I remove the avahi package without taking the system down?


-- 
Fedora release 19 (Schrödinger’s Cat)