[systemd-devel] Help with boot time debugging

Lennart Poettering lennart at poettering.net
Wed Oct 5 11:45:45 UTC 2016

On Tue, 04.10.16 20:55, Manuel Amador (Rudd-O) (rudd-o at rudd-o.com) wrote:

> Hello folks!
> I'm developing a Dracut module and I need to know how to go about
> showing what processes run by systemd during boot are saying.  This is
> for https://github.com/Rudd-O/zfs-fedora-installer .
> For example, I have this one that happens during boot:
> "Starting dracut cmdline hook"
> I want to show on the console what the cmdline hook might have spat to
> standard output.  I  want every single process that produces
> stdout/stderr/logging output to show me that output on the console.
> The boot time option systemd.journald.forward_to_console simply did not
> work (my console is a ttyS0).

Some early-boot services might turn off stdout/stderr being directed
to systemd, for some reason.

if you want live output I'd suggest using
systemd.journald.forward_to_kmsg=1 on the kernel cmdline, and then
either peek a the kernel logs via the console or netconsole...

For dracut-specific questions it's probably better to contact the
Dracut community, and Harald Hoyer, in particular (added to CC)


Lennart Poettering, Red Hat

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