Comment 14 for bug 1878596

First of all thanks for sharing the additional information.
I would assume that things worked for you on such a special disk by coincidence - such DASDs are not tested nor supported by subiquity or d-i.
We only use and test on standard 3390 models (like 9, 27, 54 etc.) and work for FBA is underway.
Can you share on how you define such a 3390 MOD60 (60 * MOD1) on zVM (incl. user direct and the dasdfmt command with the options you've used) - and which z/VM release you are using? Since I'm not aware about such kind of DASD definitions...

I 'think' CPFMTXA shouldn't be needed for Linux (just for CMS disks) - for Linux only dasdfmt (with cdl) is needed in case of DASD ECKD storage.

Regarding the parmfile - well, the parmfile is not generally limited to 80 characters, but on z/VM CMS the standard file with 80 chars is the limitation. But that shouldn't be a problem, since you can just proceed with the next line after you reached 80 characters - the linux kernel treats it all as one long line (I think the max is about 11 lines in total). Make sure you don't have unwanted spaces inside of your arguments - in case one argument spans multiple lines.
It's best to start a new line if an argument doesn't fit into the existing line - just to avoid problems.
In case one single argument itself is longer than 80 characters, well, you have to proceed with the next line. In this case the tooling is a bit tricky, since xedit shows by default the command prefix on the very left which 'eats up' some characters - I suggest to disable it to see the entire 80 characters (prefix off | on).