> I have a situation where multiple z/OS guests need to share > DASD. In the past I have used a userid as a disk holder with > MDISKs using DEVNO and MWV. > The guests would then LINK to the MDISKs using MW. It has > been suggested that I eliminate the disk holder userid and > use MDISK statements only. Each guest would then have an > MDISK for the same address. For example, MDISK D000 3390 > DEVNO D000 MWV > > Does anyone know if there is any advantage or disadvantage to > one way over the other?
Both work, but the disadvantage of the multiple MDISK definition method is that you have to keep multiple entries in multiple places absolutely in sync 100% of the time. If one is off-by-one or you forget to update one, Bad Things Ensue, and z/OS will get mucho cranky. The MDISKs will also show up as overlaps in your directory management tooling, which is OK if you understand why, but ignoring error messages is a bad habit, and you might miss an important one later if you get accustomed to ignoring errors on mapping. You've got the best (IMHO) method in place now. Don't change it. You don't need the hassle, nor does the next person to come along. -- db
