@robi you are welcome, glad you found it useful and thanks for your feedback.
I want to prevent unauthorised access to the volume when the server is offline as well as somebody who might take the server out of its rack and boot it. If the volume automatically mounts, they have full access to the data if they can circumnavigate the login cough recovery mode cough
That's covering for physical access to the machine, in what likely would be a read-only, forensic access scenario by a 'bad' actor. In my case, it's a virtualised server, so not as likely to matter, unless they move the VM to a dedicated slice to get busy with it.
Granted, this is somewhat unlikely but being paranoid is better than being sorry π
I am in the UK and storing professional data abroad (in nasty Europe no less - just kidding!) means encryption can cover the requirements nicely (as far as I know - I am not an expert in that field, so somebody please correct me if I'm wrong).