Oscar, What you're missing is what used to be called the IRG (Inter Record Gap) on physical disk records.
Now, on modern 3390 formatted disks, it is a more complicated calculation involving "cells," but it's the same idea; and only 12 4096 byte CIs will fit. Harry ________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Oscar <os...@naiandei.net> Sent: Monday, October 25, 2021 10:44 AM To: IBM-MAIN@LISTSERV.UA.EDU <IBM-MAIN@LISTSERV.UA.EDU> Subject: VSAM: Why a CISIZE of 4KB has 12 phyrecs/Track, not 13? Hi there, There's something I'm being missing, but acording to my numbers, there should be 13, not 12: Bytes per track: 56,664 bytes Bytes accessible per track: 55,996 bytes CI size: 4096 Physical record size: 4096 bytes Physical records per track (Bytes accessible per track / physical record size): 55,996 / 4096 = 13.6708984375 = 13???? What I'm missing? Thanks! -- Oscar ---------------------------------------------------------------------- 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
