Roberts, John J wrote:
So while we might have 1TB drives in our desktops, the enterprise RAID arrays are stuck at 73GB-146GB-300GB per HDA.
Actually, z/OS has supported 1TB drives (EAVs) on DS8Ks since z/OS R10, which went out of service last year. In R10 we supported VSAM, in R11 we added Extended Format sequential, and in R12 (the oldest release now in service) we added support for "almost everything else." There are still some outliers for system-level data sets (RACF DB, page data sets, NUCLEUS, etc.) but the vast majority of application data can now live happily on an EAV so long as it's read and written using system access methods.
From where I sit, the three big inhibitors to adoption seem to be a combination of disk control unit hardware support, an understandable unwillingness to reconfigure existing storage units to create larger volumes than those already configured, and an understandable reluctance to reconfigure SMS classes to make effective use of larger volumes unless necessary to support more online storage or larger data set size maximums. A somewhat distant fourth is concern about application RTOs.
My personal opinion is that over time the third reason will be overcome by the simplification aspects of managing a small number of large volumes rather than the other way 'round, but time will tell.
-- John Eells z/OS Technical Marketing IBM Poughkeepsie [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
