[systemd-devel] systemd diagnostics

[Edward Z. Yang]

Hello Gustavo,

Of course!

Excerpts from Gustavo Sverzut Barbieri's message of Tue Nov 22 04:49:00 -0500 2011:
> > 1. Newline separated property information.  When I run
> > 'systemctl show -p "Wants" basic.target' I get a space-separated list of
> > targets.  This is pretty annoying, it would be great for it to be newline
> > separated.  Maybe another command for this use-case of inspecting
> > dependencies.  (It's also pretty confusing to tell whether or not I want
> > Before or Wants.)

Primarily useful when developing and debugging systemd unit files. It's
not always obvious what the correct set of dependencies are and a good
way to figure things out is to see how the system is currently structured.

> > 2. Dependency chasing for "Wants".  If I enable some systemd service,
> > I would like to know all of the extra services it spins up.  systemd
> --test --system
> > doesn't really do what I would like here.  I actually want something more
> like
> > iterated 'show -p "Wants".

Ditto. Also, useful when a dep is not getting run and you're not really sure why.

> > 3. Listing enabled services.  We should not have to write horrible
> > scripts like this:
> >
> >    for SERVICE in `systemctl -t service --full --all list-units | awk '{
> >    print $1 }'`; do
> >        echo -n "$SERVICE:  "
> >        if systemctl is-enabled $SERVICE; then
> >            echo ENABLED
> >        else
> >            echo disabled
> >        fi
> >    done 2>/dev/null

We maintain around ten servers, and sometimes things get out of sync, so
part of our auditing procedure is to ensure all the same services are
enabled on all of the machines.

> > 4. Fedora 15 shutdown does not give any messages to the console (my
> coworkers
> > tell me this is a funny Plymouth interaction.)  Did this get fixed later
> on,
> > or do we need to do something else?

This is just a little annoying, since console is the most convenient
way of interacting with a rebooting VM, and we have historically had cases
where kernel modules would BUG during the reboot process (or
other bad thigns) and it would be nice know about it.

Edward