Tom, I believe the change occurred with the RAMAC volumes and not the 2105. EMC made it a default in one of the Microcode upgrades in late 1995, and HDS provided an option to format volumes as 3390-3R in the 7700E and beyond.
It made life a bitch for allocation where RAMAC and non-RAMAC devices were in the same STORCLAS until DFSMS was changed (1.3 I think) introduced NOPREF for the AVAILABILITY option. With PREFERRED, allocation would go to all the volumes responding as RAMAC in the RDC, and STANDARD would prefer the non-RAMAC volumes. The balance of the STORGRUP was not used until allocation dropped through the primary EDL because the space thresholds were blown. It created some irritating performance issues at a Telco I worked at in Australia when the first EMC box was upgraded and all the activity for a half dozen LPARS started landing there - someone had specified PREFERRED in the STORCLAS when there wasn't a RAMAC within cooee of the place. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of Tom Moulder > Sent: Tuesday, July 31, 2007 10:12 AM > To: [email protected] > Subject: Re: [IBM-MAIN] EMC DMX3-1500 and REFORMAT VTOC > > Alternative tracks are actually provided for in the controller and were > last > used in the 3990-6. The advent of 2105 controller and emulation of it by > disk arrays had no microcode to take advantage of/or use alternate tracks. > > When you reformat the VTOC, this process in no way compromises any data on > the volume. However, I understand that if this has not been done before > now > that it might appear to be a nuisance issue. > > Tom Moulder > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
