error message 'su: authentication failure' while trying to become super-user


May 11, 2020
I want to run nextcloud occ-commands within a pod shell and followed the descripition in this thread. It worked fine within my test-installation about a month ago. Today I did a fresh installation of TrueNAS-SCALE- on my productive server and I wanted to move my data from core to scale. In this fresh installation I always get an error message while trying to run su.

admin@scale$ su Password: su: Authentication failure admin@scale$

I tried the scale shell via System Settings, via Putty and within my nextcloud pod. I always get the same error after entering the password. I activated the root-user and I did run su within the scale shell in the web GUI and in Putty as root. Every time I need to authenticate su with my password I get the authentication error above.

Running sudo -i works fine as admin-user. Only su authentication fails.

Any hints, what might be wrong are welcome!

Thanks, tj