To answer tkaiser's question first -
root@locker:~# cat /proc/device-tree/model
Marvell Armada 375 Development Boardroot@locker:~#
root@locker:~#
root@locker:~# uname -a
Linux locker.trisect.eu 4.9.2-armada375 #1 SMP Mon Jan 23 16:52:54 CET 2017 armv7l GNU/Linux
...why not NFS? I'm trying to set up some remote backup storage for a server, why shouldn't I use NFS (seems the easiest option)?
Now to update -
I've given it one more try and have found an error (of my own making) that, now fixed, has enabled me to create shared folders. The latest problem is that although NFS is enabled it's not running. Also something called rrdcached is hammering the CPU (and has been for some time)