I am attempting to get a sub-4gb image to retain its image size on my rpi regardless of the sdcard size. I am looking at using the ubuntu server image built by Ryan Finnie ubuntu-16.04-preinstalled-server-armhf+raspi3.img from the ubuntu wiki
The suggestion in Temporarily disable expand filesystem during first boot by goldilocks of disabling of
/boot/cmdline.txt works on Ubuntu Mate.
But the server image does not have the
/boot/cmdline.txt - but first boot expands the image to the max capacity of the card.
Does anyone know where the partition resize is triggered on this ubuntu server image?