The default value is set to preserve all data saved by netbox. As
explained in the manpage, it sets the directory for all data directories
to `~netbox/data/` (would resolve to `/opt/netbox/data/`), so upgrades
will not remove this data.
The secret key is generated if it is not set via parameter and the
explorer does not return any. It will be saved in the netbox home
directory to easily read the key for the config generation.
matze
fnux