As usual there is no one right answer. It all depends on your z/OS product mix. In our case, all IBM products except CICS and DB2 are managed in the same Target zones. I personally prefer a single sysres volume that contains all target and associated ZFS files. We recently outgrew mod-54 and are now on 1 TB EAV’s for SYSRES volumes. They are thin provisioned, so its not like we are wasting the unused space.
Dave Jousma Vice President | Director, Technology Engineering From: IBM Mainframe Discussion List <[email protected]> on behalf of Peter <[email protected]> Date: Monday, July 21, 2025 at 11:56 PM To: [email protected] <[email protected]> Subject: z/OS 3.1 upgrade - res volume Hello All I am planning to upgrade z/OS 2.4 to z/OS 3.1. Some of the prerequisite like SDSF migrationt to RACF security and TCPIP interface statement have taken care. Ours is monoplex with just 1 production lpar and 1 test lpar. Not a big shop with multiple IBM products, we are an adabas shop with adabas database and Natural product. What would be the ideal size of res volume for z/OS 3.1 ? I am thinking about mod27. If someone has performed an upgrade from 2.4 to 3.1 , please do share your thoughts as I am already looking through the migration manuals. Any pointers would be appreciated. Regards Peter ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN This e-mail transmission contains information that is confidential and may be privileged. It is intended only for the addressee(s) named above. If you receive this e-mail in error, please do not read, copy or disseminate it in any manner. If you are not the intended recipient, any disclosure, copying, distribution or use of the contents of this information is prohibited. Please reply to the message immediately by informing the sender that the message was misdirected. After replying, please erase it from your computer system. Your assistance in correcting this error is appreciated. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
