A full pack minidisk is not eligible for MDC. (Note 6 under MINIOPT in the 6.1 Planning and Admin. Book). Also, a minidisk greater than 32767 (CKD) cylinders is not eligible.
Regards, Richard Schuh > -----Original Message----- > From: The IBM z/VM Operating System > [mailto:ib...@listserv.uark.edu] On Behalf Of Phil Tully > Sent: Wednesday, January 27, 2010 1:03 PM > To: IBMVM@LISTSERV.UARK.EDU > Subject: mdcache > > I have over the past couple years specifically limited the > use of mdcache= in most systems because of the lack of > sharing across virtual machines. I h= ave been experimenting > with the enabling mdcache for a limited subset of mdis= ks > which are used (r/o) across multiple guests. > > I have added miniopt mdc into the directory entry for the > shared mdisk. > > I have issued set mdcache rdev for the devices the mdisks are > defined on.= > > > mdcache is on for the system , with 2000m min 9000m max (96G > real storage= > ) > > > I start i/o to the mdisk using ddr, but I see no mdcache usage. > > Is there something that will block an mdisk from being cached? >
