[systemd-devel] systemd footprint

[Kay Sievers]

On Sat, Dec 3, 2011 at 23:31, Holger Winkelmann <hw at travelping.com> wrote:
> We are about to renovate our embedded toolchain a bit and consider to integrate
> systemd as init. We are a bit concerned about the DBUS dependency in systemd as
> we have to meet a 4-8 MB hard disk (flash) requirement,
>
> I read about some other folks have used systems for embedded devices, but it seems
> mor for mobile devices rather then networked sensor devices or similar.
>
> What would be the best approach to scale down to this devices? Is DBUS a hard
> requirement? I also can imagine that a pure console based Server OS would not have BDUS either?

For very simple setups, the D-Bus bus daemon is not absolutely
necessary, and can probably be made optional with a few changes, but
the D-Bus protocol is used by systemctl to talk to systemd, and can
not really be optimized out.

> What are the plans for the server OS i,e, REHEL if systems becomes standard for the distributions?
> currently this all sounds in many parts Desktop centric but has a lot of potential for
> embedded or server uses cases.

D-Bus is in not desktop centric, it's a plain IPC mechanism which lets
processes talk to each other. It's just that the desktop is not as
simple in its task as the usual base OS, so that it needs more
advanced technology like IPC and an object model to let components
integrate with each other.

For server OSs, and any other commonly used setup, there will be no
installation of systemd without D-Bus. It just can't work.

Simple and limited embedded-like setups could work without the D-Bus
server, but still not really without the D-Bus protocol.

Kay