It would be best for a unique password to be generated for shell access and presented to users the first time they boot the device, like it's currently done when using the ownCloud VM.
Root user has a strong pre-generated pass that are stored as a file inside the owncloud dir with www-data permissions so that it's accessible inside ownCloud (maybe not so safe, but an option)
Same goes for the regular user (or make a simple change_pass.sh script for the regular user that can be run from SHELL
It would be best for a unique password to be generated for shell access and presented to users the first time they boot the device, like it's currently done when using the ownCloud VM.
@enoch85 has posted this: