@sebastian-roth while your reply was a bit cryptical in the sense that I had no idea what FOS init was I went down the rabbit hole of trying to upgrade our FOG-server.
Lets just say: Not trying that again. My old FOG-server was initially build in a 0.xx version (I think) and was running on Ubuntu 14. Eons ago I made something for a co-worker to make it possible to simply mass-deploy images.
Fast-forward to 2022 with new hardware “the new guy” complaint about the old tool how it didnt resize drives.
I just bit the bullet and build a new VM, installed a 1.5.9 FOG from scratch, recaptured the image to this new server and it just works.
I’m not going to try and debug a Ubuntu 12 to 14 update-on-update FOG-installation, so thanks for your help - the new FOG-version runs perfectly fine for our task