Willie, Just gleaning from the various replies on the list (without actually doing any research of my own), the answer is "it depends" - are you looking at a single volume VSAM dataset? If so, I believe the 65536 track (about 4369 cylinders) is the max - nothing to do with the fact that it is VSAM, just the limit of tracks on a volume - well under the 4 GB (or GiB) limit.
If you are looking at a multi-volume dataset, it depends on your CI size and the accompanying physical block size of the dataset which changes the amount of data that can fit on a single track or cylinder. Rex -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of willie bunter Sent: Wednesday, October 22, 2014 8:35 AM To: [email protected] Subject: Re: QUESTION ABOUT VSAM / VSAM EXTENDED Thanks to everybody's input. However, I still don't have a firm answer. What is the maximum amount of cylinders should I be able to allocate for a VSAM DSN without having to make it EXTENDED. Would this be the same critera for OAM dsns as well? -------------------------------------------- On Wed, 10/22/14, Roberto <[email protected]> wrote: Subject: Re: QUESTION ABOUT VSAM / VSAM EXTENDED To: [email protected] Received: Wednesday, October 22, 2014, 9:09 AM Hi to every, NO! A VSAM with CIsize of 4096 can use only 12 block on every tracks so in a cyls is possible to write 4096*12*15 => 737.280 byte or 720KB 4GB are 4294967296 byte / 737280 are about 5825 cyls (or 87381 tracks) Remember the space limit of 65536 track on every volume for any dsn not in extended format. (about 4369 cyls) I hope this clarify some requirement of VSAM on dasd Best Regards Roberto Il 22/10/2014 14:40, Chase, John ha scritto: >> -----Original Message----- >> From: IBM Mainframe Discussion List On Behalf Of John Eells >> >>> What is the maximum number of cyclinders that can be used to define a dsn that is not VSAM EXTENDED. >> I think it is 4400 cylinders. I was trying to allocate a dsn at 4500 4500 but I kept on abending with >> IGD17273I ALLOCATION HAS FAILED FOR ALL VOLUMES........ >>> Finally I was able to allocate the dsn at CYL(4350 4350). >> z/OS DFSMS Using Data Sets documents maximum data set sizes, including limits for both extended format >> and nonextended format VSAM data sets, in Topic 1.3.2.3. It says that nonextended VSAM data sets have >> a limit of 4GB*. >> >> (4GB* / 56664 / 15) = 5,053 cylinders (approximately) >> >> [ snip ] >> >> * I believe that is most likely GiB for the pedantic among us. > IIRC, DASD capacities are expressed in decimal, rather than binary, quantities: > > 4KB = 4,000 bytes; > 4MB = 4,000,000 bytes; > 4GB = 4,000,000,000 bytes; > Etc. > > -jc- > > ********************************************************************** > Information contained in this e-mail message and in any attachments thereto is confidential. If you are not the intended recipient, please destroy this message, delete any copies held on your systems, notify the sender immediately, and refrain from using or disclosing all or any part of its content to any other person. > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN The information contained in this message is confidential, protected from disclosure and may be legally privileged. If the reader of this message is not the intended recipient or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any disclosure, distribution, copying, or any action taken or action omitted in reliance on it, is strictly prohibited and may be unlawful. If you have received this communication in error, please notify us immediately by replying to this message and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
