I'd be surprized thay must be 3380's: DFSMS overrides them dynamically to match source and target MDISKs when it moves a CMS disk to a new place. And, at that time it will get the device type, start, and size of the source/target.
DFSMS was the first to use this trick, it avoids several calls to DIRECTXA, so improves performance on systems with large directories. Dirmaint R5 later copied this technique. 2010/5/27 Alan Altmark <alan_altm...@us.ibm.com> > On Thursday, 05/27/2010 at 01:34 EDT, Mark Pace <mpac...@gmail.com> wrote: > > I'm confused. > > The DFSMS program directory has a note > > Critical Information > > The 500 & 5FF minidisk must be 3380 dasd. Emphasis IBM's. > > mdisk 0500 3380 001 001 $$$$$$ MR > > mdisk 0500 3380 001 001 $$$$$$ MR > > > > Yet the sample directory entries provided in VSM221B PLANINFO have 3390 > as the > > devtype. > > mdisk 0500 3390 001 001 $$$$$$ MR > > mdisk 0500 3390 001 001 $$$$$$ MR > > > > Is the program directory incorrect or is the provided sample incorrect? > Does > > it really matter? > > Yes, it matters. In order for CP to instantiate a minidisk, the vdev type > must match the rdev type. I suspect that the 'must be 3380' is really > 'must be modern ECKD that supports the stuff I need'. > > While not relevant in this particular case, the device type on the MDISK > tells DIRECTXA what the highest cylinder number is for that volume > (remembering that the volumes are not necessarily available to DIRECTXA > when it is being run). > > > Alan Altmark > z/VM Development > IBM Endicott > -- Kris Buelens, IBM Belgium, VM customer support
