Mike, I don't see where the link mentions the 4KiB physical block limitation as 4KiB.
It does not match with the physical record size used in my sample listcat. This item does not give the calculation method, but it shows how CI uses multiple PB. https://www.ibm.com/support/knowledgecenter/en/SSLTBW_2.1.0/com.ibm.zos.v2r1.idad400/d4222.htm Ron -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Mike Schwab Sent: Tuesday, January 16, 2018 3:08 PM To: [email protected] Subject: Re: [IBM-MAIN] VSAM Performance - CPU reduction https://www.ibm.com/support/knowledgecenter/SSLTBW_2.1.0/com.ibm.zos.v2r1.idad400/ciopt.htm Physical blocks in a CI is multiple of 512 up to 4096 bytes. On Tue, Jan 16, 2018 at 11:00 AM, Clark Morris <[email protected]> wrote: > [Default] On 16 Jan 2018 06:54:52 -0800, in bit.listserv.ibm-main > [email protected] (Ron hawkins) wrote: > >>Tim, >> >>Things changed a couple of decades ago. >> >>VSAM physical block is not always the same as the CISZ. >> >>32K CISZ does not waste any space on the track. > > Where is this written up? Being retired, I missed this and didn't > realize this was true on the OS390 system I worked on in the 1990s. > > Clark Morris >> >>Ron >> >>---------------------------------------------------------------------- >>For IBM-MAIN subscribe / signoff / archive access instructions, >>send email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
