MDFS Setup
Started by setting up the main MDFS unit, and attaching the floppy drive unit to it.
After some searching on the internet found the manual for it.

Now connected my serial cable (which is a standard PC 9 pin to 5 pin DIN connector on the MDFS side), luckily this is the same as the BBC and I managed to find my already wired cable so didn't require soldering a new one.
The MDFS has the coolest on button (or rather a key). To start the server in normal mode you turn it to "Secure" or to "System" if you want to be able to enable "Utility Mode" or access certain functions from a networked BBC once it is running.
To stat off I turned on the MDFS an put the key to the "System" setting.

The power light now comes on and the "Discs Free" light starts to flash.

Now I started a terminal emulator and connected it to COM3 of my PC, pressing return gets a response from a monitor program that is ready to load the main system.

Now I inserted the system boot disk and pressed the "Release Discs" button on the front of the unit.

The disk drives are now polled and the system loads the main boot code from the disc, the "Discs Free" light now goes solid and the "Utility Mode" light also comes on.

At this point if I press return on the terminal I get the following menu.

There are various options available including "Boot the fileserver" which take the system out of utility mode and starts serving files on the network. If I mounted another disk you can serve just floppy discs to the network (this is what the original Acorn fileserver did).
Next I added the hard disc unit and the tape system unit to the stack.

On rebooting I found that the system will boot from the hard disk as it already has the boot code required installed, this means I don't need the floppy disk anymore.
Checking The Discs
After booting back into utility mode I used the "L" item on the menu to check the discs on the system, it turns out that I have 3 hard discs and a tape drive (I didn't realise the tape unit had a hard disc inside).
The discs reported are...
FUJITSU M2611S
Ver 0703
F : Name: FS1 41600K
SEAGATE ST277N-1
Ver 040C0800
I1: Name: FS2 61360K
I2: Name: FS3 1040K
FUJITSU M2616S
Ver 1002
J1: Name: FS4 61360K
J2: Name: FS5 36400K
So there is a 40Mb, 60Mb and a 100mb drive split into 5 partitions.
I also tried to access the tape drive but this doesn't seem to want to work, I have a spare brand new unit in storage so I will bring that over and try it.
Also ran the verify on the discs, F is fine, J has one block on partition 2 that its not happy about and drive I seems totally on is way out. (Too be honest the drive doesn't sound that good).