Re: LUKS question

[Tim]

Allegedly, on or about 12 December 2017, Robert Nichols sent:
> You can do that with cryptsetup-reencrypt, but it needs to be able to
> make space for the ~2MB LUKS header ahead of the filesystem in the
> partition. That's a fairly risky operation -- shrinking the
> filesystem slightly and shifting it over. An alternative is LUKS with
> a detached header, but maintaining that relationship is an
> administrative headache with a severe penalty for error.

If they had the spare drive space, I'd suggest shrink the existing
partition in half.  Make a new encrypted one in that new space.  Copy
the files over.  Erase the previous partition, and either keep it for
the next lot of jiggery-pokery, or expand your new one into the space.