However, David - you wrote, that my understanding is/was good for real tape drives (standalone), but TS7700 changed the game rules. That means "foreign" (non-sysplexed) systems can autoswitch virtual tape devices (with no additional software). Have I understood it correctly?
That is correct. Please reread the post that Scott Ballentine made on this topic. ________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Radoslaw Skorupka <[email protected]> Sent: Friday, May 30, 2025 4:12:52 PM To: [email protected] <[email protected]> Subject: Re: Autoswitch Maybe it's my poor English, but I'm not sure. Paul Feller in the message below confirmed that autoswitch is working inside the sysplex. And few sysplexes share VTS installation, but each of the sysplexes use it's own, statically (manually) assigned set of devices. That's what I mean. Indeed, autoswitch between sysplex members is working with no additional software. However, David - you wrote, that my understanding is/was good for real tape drives (standalone), but TS7700 changed the game rules. That means "foreign" (non-sysplexed) systems can autoswitch virtual tape devices (with no additional software). Have I understood it correctly? AFAIK the autoswitch inside sysplex does use/require sysplex communication. I cannot imagine why the communication is required between sysplex members, while non-sysplexed z/OS images can autoswitch devices with no communication. Exempt from z/OS 3.1 documentation: With z/OS Release 2 and higher, the ATS STAR design improves the availability and system management characteristics of the previous automatic tape switching function. ATS STAR does not use the IEFAUTOS structure but instead uses global resource serialization and XCF services to maintain serialization when it allocates shared tape devices. To maximize the performance of the ATS STAR function, use the global resource serialization STAR configuration rather than the ring configuration. Fun fact: I have found similar discussion in the archives of IBM-MAIN. It was 20 years ago and I was one of the participants. :-) A member of DFRMM development suggested IBM ATAM for cross-sysplex. Of course it was 20 years ago, things could have changed, but I never heard about such change. I would be happy to find some confirmation about the change - technical details, chapter in manual, presentation, anything. Regards -- Radoslaw Skorupka Lodz, Poland W dniu 30.05.2025 o 14:28, Jousma, David pisze: > Radoslaw, you said: “Yes, autoswitch does not require MIM. However > autoswitch will not work across sysplex boundaries.” > > This is not correct with regards to TS7700 series tape libraries. It does > work across sysplex boundaries without additional software. You are correct > with regards to stand alone tape drives I believe. Not sure how much of that > is still around though. > > > > Dave Jousma > Vice President | Director, Technology Engineering > > > > > > From: IBM Mainframe Discussion List<[email protected]> on behalf of > Radoslaw Skorupka<[email protected]> > Date: Friday, May 30, 2025 at 8:12 AM > To:[email protected] <[email protected]> > Subject: Re: Autoswitch > > > > W dniu 29.05.2025 o 13:58, Jousma, David pisze: > >> AUTOSWITCH does NOT require GRS/MIM, etc to work inside or outside the >> sysplex any longer. We have same tape drives online to 5 different >> sysplexes. > > > Again: it is NOT ABOUT GRS/MIM. > > Yes, autoswitch does not require MIM. However autoswitch will not work > > across sysplex boundaries. > > However there are software products which allow it. > > Product names are IBM ATAM (Automated Tape Allocation Manager) and CA-MIA. > > Both are licensed (and paid) products. > > > > > > And still, having dozens of virtual drives allow user to assign the > > drives statically and forget about the issue. > > ---------------------------------------------------------------------- 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
