Been investigating why the new swap feature isn't working.
Tested with appliance as follows:
As you can see from the logs, the extra device is created and the swap command is run along with various other gubbins to make it valid swap (grep swap):
Unfortunately, you can see it results in the following useless fstab which has no label.
Naturally /proc/swaps is empty.
Fixing it in-image is trivial. I simply re-ran mkswap with labelling `mkswap -L SWAP /dev/sda1` and jammed it into /etc/fstab, then `swapon SWAP`. In this example the device name is /dev/sda2
I then tested it worked as expected, to do this I set high swapping behaviour
Then ran a benchmark that ate ram. Worked a charm, so the device itself is working fine.