Where are my sshd logs?

Try this command to view the log from systemctl:

journalctl -u sshd |tail -100

A better way to see the last part of the log is:

journalctl -u sshd -n 100

Using tail on the output of journalctl can be very slow. It took 5 minutes on a machine where I tried it, while the above command returns instantly.

I have found the output of sshd and other core services in 'journalctl'.

See more at the Arch Wiki entry for systemd:

https://wiki.archlinux.org/index.php/Systemd/Journal