[arch-general] How to show (kernel) messages by journalctl?

[Timothée Ravier]

On 13/10/2013 01:51, Ralf Mardorf wrote:
> yesterday I rebooted at 17:51 from linux 3.11.4-1 to linux-rt
> 3.10.14_rt9-1 and then shut down at 17:55.
> 
> How can I get log data, kernel messages of this startup?

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

Tim