... > MVS and its successors "know" how 3390 track geometry is supposed > to work. So the emulated DASD controller must emulate the "overhead" > so that "too much" data does not go onto an emulated track. > Things like TRKCALC and other access methods depend on an > emulated track only getting "x" blocks on a single track ...
[sigh] Another datapoint indicating that MVS should learn FBA. But it's a losing battle. There seems to be some unwritten law that says "disk" on "channel" must be [E]CKD, so that while VM, VSE, Linux, and others are happily embracing fixed block disk, the mainframe channel-attached "disk" MARKET stays constrained. Mainframes would be booting directly from CD-ROM without such peculiarities as OMA if we had acceptable FBA disk. There would be no odd capacity losses from smaller blocks if we had acceptable FBA support. [moan] [grone] [ANGST] See other note. -- R;
