[systemd-devel] Options for logging from service started before journald?

[Jan Alexander Steffens]

On Sun, Oct 18, 2015 at 5:05 PM, Andrei Borzenkov <arvidjaar at gmail.com> wrote:
> What can be done to log from unit that needs to be started before journald?
> Journal, syslog or kmsg all require journald connection and as far as I
> understand will deadlock on waiting for journald to accept it. NULL is not
> an option; is tty the only choice left?
>
> Background - openSUSE tries to start haveged before journald to add
> randomness.
>
> This sounds like reincarnation of "how to log to syslog and be started
> before syslogd". This was solved by moving logging connection to journald
> and starting it very early. May be something like minilod or blogd that
> buffers output until journald is started would be appropriate here?

You can log into the kernel's log buffer, see
https://www.kernel.org/doc/Documentation/ABI/testing/dev-kmsg