Why wouldn't they be totally compatible? I would think that striping occurs at a much lower level than QSAM (probably EXCP or lower? maybe "Media Manager" level?) so one would expect that QSAM wouldn't even know it was happening.
More sophisticated utilities like SORT may be aware of striping, but such utilities are expected to DTRT as well because they are far more aware of system-level efficiencies. ISTR that IBM and Syncsort in the days of real CKD devices regularly one-upped each other by patenting more and more sophisticated and efficient CCW sequences. I never did know who won that particular game, or if it even matters in the final analysis now that real CKD are gone. Peter -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Paul Gilmartin Sent: Monday, March 8, 2021 12:42 PM To: [email protected] Subject: Re: Large block interface for VB EXTERNAL EMAIL On Mon, 8 Mar 2021 11:15:56 -0600, Nigel Morton wrote: >Have you considered using extended format sequential striped data sets? > >Define using a data class with DSNTYPE set to require or request extended >format; control the number of stripes (which are read in parallel) using a >storage class with a non-zero sustained data rate attribute. Choosing the >value of the sustained data rate is a little clumsy but, in brief, 8 gives two >stripes and 12 gives 3 stripes for 3390 device geometry. > >Last time I looked, the throughput scaled roughly linearly with the number of >stripes. > I stand corrected vis-à-vis my pessimism: On Sun, 7 Mar 2021 15:42:33 -0600, Paul Gilmartin wrote: > ... >Don't know about striped RAID. I suspect there's no software support >for the desirable parallel I/O. Are such data sets compatible with Classic utilities such as IEBGENER or Assembler programs using QSAM? -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
