I was curious about this aspect, as well. Since 3390 emulation is just emulation, and usually the number of cylinders in the physical device do not match the number being emulated, the layout on the cylinder on the emulated 3390 (defined in JCL) is nothing like how it is actually stored on the physical device. So expecting something to be on a cylinder boundary seems likely wrong.
This shortcoming seems to apply equally to a DS8000 as any other device such as an EMC. What's more, on some physical devices, there's no such thing as a cylinder. Or am I way off base? David G. Schlecht | Information Technology Professional State of Nevada | Department of Administration | Enterprise IT Services T:(775)684-4328 | F: (775) 684‐4324 | E:dschle...@admin.nv.gov -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Mark Zelden Sent: Thursday, February 06, 2014 10:45 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: RES: Implicit VVDS creation One of the reasons to do it implicitly is placement, not that it really matters, but if you want it next to the VTOC you may want to do it implicitly. On Thu, 6 Feb 2014 18:01:51 +0000, ITURIEL DO NASCIMENTO NETO <4254.itur...@bradesco.com.br> wrote: >Since z/OS 1.13 there is a new IGGCATxx member in PARMLIB that can be >used to specify VVDS default space, among other parameters. Even though the storage team implicitly defines a VVDS at the shop I spend time it (usually?), we had this command in place prior to z/OS 1.13: F CATALOG,VVDSSPACE(30,15) So 3x larger for primary than the default TRK(10,10). Now we have it in IGGCATxx since z/OS 1.13 as mentioned. VVDSSPACE(30,15) /* DFLT IS 10,10 */ Mark -- Mark Zelden - Zelden Consulting Services - z/OS, OS/390 and MVS ITIL v3 Foundation Certified mailto:m...@mzelden.com Mark's MVS Utilities: http://www.mzelden.com/mvsutil.html Systems Programming expert at http://search390.techtarget.com/ateExperts/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
