Querying systemd journal

systemd is the modern init system used on many Linux distributions, including Ubuntu. The command to query systemd’s journal is journalctl. Querying the journal is useful to find out about previous boots and to look at logs of what apps went wrong.

• Show the logs of the journal in a pager:

$ journalctl

• List all previous boots and their timestamps:

$ journalctl --list-boots

This can be useful to see your previous uptimes.

• The journal tends to be long, so you might need to scroll all the way down to see the most recent log. To start at the end of the log:

$ journalctl --pager-end

• The journal has the logs of all the previous boots. To see the logs of a particular boot, provide its number X from --list-boots:

$ journalctl --boot=X

Tried with: Ubuntu 18.04