Although HFS is now deprecated in favor of ZFS, there are still a lot of HFS around, so a note might be in order. HFS is a special implementation of PDSE that is *not* subject to the single-volume restriction. We hit a problem early on with multivolume HFS when allocation failed despite doc to the contrary. IBM discovered that allocation logic was checking data set attributes in the wrong order. They were checking for 'PDSE' attribute before 'HFS' attribute and rejecting multivolume. The APAR fix reversed the order of checks, so multivolume HFS was OK.
. . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 323-715-0595 Mobile 626-543-6132 Office ⇐=== NEW [email protected] -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Farley, Peter x23353 Sent: Monday, February 20, 2017 8:49 AM To: [email protected] Subject: (External):Re: Maximum size of a PDSE library? Many thanks for the follow-up Radoslaw. I am pursuing the issue of creating an EAV of sufficient size for our purposes with our Storage Admins now. Unfortunately I do not know the limits (or even the HW vendor) of our DASD system, so I do not yet know what we will be able to do. Fortunately our immediate issue is not member size but total dataset size, so using a V2 PDSE won’t be needed until we determine whether to use member generations or not. That's a different can of worms. Peter -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of R.S. Sent: Monday, February 20, 2017 8:47 AM To: [email protected] Subject: Re: Maximum size of a PDSE library? W dniu 2017-02-17 o 17:08, Farley, Peter x23353 pisze: > Thanks for the reference, Tom. But what about total PDSE size? Can it > exceed 4Gb uncompressed? Obviously compression is a viable option too, but > it would be helpful to know the actual cylinder/Gb size limit (assuming there > is one). It's complex a little bit PDSE was *never* constrained to 4GB or 64k TRK. PDSE was and still is constrained to one volume. It can be 3390-9, so called mod-27 and mod-54 and EAV as well. The limit for EAV is 1TB now, it can be limited by your DASD configuration. There is also a limit for PDSE member size. For PDSE v.1 it is 15 728 639 records (approx. 1.2GB for FB 80). However since z/OS 2.1 there is v.2 of PDSE with limit for member at 2 146 435 071 records (approx. 171 GB for FB 80). There is also a limit for number of members, it's 522 236. For record purposes, limits of regular PDS are: single volume, 64k TRK per (single) volume). Member is limited only by the size of PDS, number of members are limited by directory size. Huge directory provides really poor performance. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
