He he he, I had to install zOS a few years ago.. You think fixing a defect on zvm/zlinux is a PITA, just try installing zOS. Ugh, make me shiver thinking about it.
Apparently, just cloning a working system and applying PTF's is the common method of doing it. Otherwise you can pay IBM to build an image and install it (can't remember what they call it) but basically they generally install it the same way.
Oh man, I can only imagine. As far as fixing a defect on zLinux, that was usually something that made be breathe a slight sigh of relief. It meant I would be doing something on a somewhat sane and modern system that behaved roughly like something I'm used to.
Apparently, just cloning a working system and applying PTF's is the common method of doing it. Otherwise you can pay IBM to build an image and install it (can't remember what they call it) but basically they generally install it the same way.