[systemd-devel] Journald : from initialramfs to real root

[Thomas HUMMEL]

Hello,

I'm running systemd-239-74 on RHEL 8.8. EUS.
I'm using dracut initialramfs running systemd to PXE boot stateless 
compute nodes.

In real-root image, journald is set up to forward to syslog 
(ForwardToSyslog=yes) which is handled by rsyslogd to aggregate on a log 
server logs from nodes.

So I can see in those logs kernel booting messages (starting with

kernel: [    0.000000] Linux version 4.18.0-477.43.1.el8_8.x86_64 
(mockbuild at x86-vm-07.build.eng.bos.redhat.com) (gcc version 8.5.0 
20210514 (Red Hat 8.5.0-18) (GCC)) #1 SMP Thu Jan 4 10:30:57 EST 2024

)

I also sometimes used dracut debug mode and initialramfs journald as 
stated in the man:

" rd.debug
            set -x for the dracut shell. If systemd is active in the
            initramfs, all output is logged to the systemd journal, which
            you can inspect with "journalctl -ab". "

I was wondering :

1. is initialramfs journald able to somehow handle its logs to actual 
root systemd and if so how ? (my understanding was that, for instance, 
such a mechanism was a reason to use dracut NetworkManager (as opposed 
to legacy module) module if/when using NetworkManger in actual root)

2. would then initialramfs output also be forwarded to syslog ? Only in 
debug mode ?

Thanks for your help

-- 
Thomas HUMMEL

-- 
Thomas HUMMEL
HPC Group
Institut PASTEUR
Paris, FRANCE