To get log data from a specific startup, as root/using sudo, run:
# journalctl -b -1 "_TRANSPORT=kernel"
where "-b -1" means the previous boot ("-b -2" meaning the boot before
and so on).
You can also use:
# journalctl -b -0 "_TRANSPORT=kernel"
to show current boot messages, which is equivalent to:
# journalctl -k
Thank you Tim, Chris and John :) Regards, Ralf
