[arch-general] libsystemd to systemd

[Tom Gundersen]

On Fri, Aug 31, 2012 at 12:44 PM, Kevin Chadwick <ma1l1ists at yahoo.co.uk> wrote:
> While the cause has been explained I think we are missing the Why or is
> it How.
>
> If dbus was out of order how come it worked under initscripts?

I have honestly no idea why the setup used to work (it never should
have), and what made it stop working (nothing should have changed).
Notice that the OP is still using initscripts. My best guess is there
was a race and somehow something sped-up or slowed down to make it
trigger.

> Is
> it because initscripts checks the list and starts dbus early in any case
> and the init script compatibility over-rid systemds similar behaviour?

Under initscripts all daemons are started exactly in the order given
in the DAEMONS array. With the exception of udevd which is started
unconditionally early on in rc.sysinit and does not have an rc script.

Under systemd the ordering is given in each of the service files, dbus
comes with its own service/socket files so that should be started
correctly (the socket is started very early on so it is always
available from the point of view of all the other daemons).

If you use systemd with the initscripts compatibility layer (i.e., you
have some rc scripts that don't yet have equivalent native systemd
service files), then the ordering of when to start them is taken from
the DAEMONS array as in initscripts. Notice however, that this is the
last fallback, and the ordering information given in any available
native service files take precedence.

People are grumbling about this compatibility layer, and I might
change/remove it at some point. The reason I still have not ripped it
out is that I like the fact that your system will "just work" as
before if you add init=/bin/systemd to the kernel command line.
Without the compatibility layer you'd have to also enable the relevant
services (I guess that's not too much to ask though...).

> I assumed they were used a little, if they are unused why are they
> required, dependencies?

Not entirely sure what you are asking. systemd-tools used to be a
dependency of initscripts (it is used all over the place), now
systemd-tools was merged into systemd, so systemd is a dependency of
initscripts. Does that answer your question?