Hi Tom, 1. A Metro Mirror within a single DS8k Where set H1 clones to H2. This first idea, I have not done that so I am not sure that is possible. In establishing the MM session you usually need to put in the target serial number such as IBM-2107.75ABC12 and the source serial number as well as the source WWN. Perhaps someone else can comment on whether these can be all the same DS8K, I don't think so but I could be wrong. Internally within the same DS8K I have always set up FlashCopy relationships not MM relationships.
2. Establish a second Global Mirror from H2 to the new DS8900F - H3 Yes very possible, one of my current clients is doing this now for their DR position to their remote DR site. H2 volumes can certainly be both target MM volumes and source GM volumes. There are potential pitfalls that need more research 1. Can H2 be Space Efficient volumes in a Internal Metro Mirror or do they have to be fully configured for space? I would think the H2 volumes need to be normal volumes especially if you are going to be using them as source GM volumes to go H2 to H3. The only space efficient volumes I have set up for GM sessions are the GM Journal Volumes. Those you want as space efficient as they will never grow as big as normal volumes unless of course something unexpectedly dramatic happens. 2. Can the H2 be both the target of a MM *and* the source of a GM relationship? Yes, already answered. 3. Does this expose us to buying additional capacity licenses for the Copy Services license? No idea, sorry. Perhaps if you check your licensed features on the DS8K GUI it will show you how many TB of space you are licensed for to confirm if you need to increase your licenses or not. Hope that Helps -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of Tom Longfellow Sent: March 19, 2022 2:12 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: DS8K Global Mirroring - dual targets Yes, that reference looks very close to what I want to do. It has been drummed into me with the replies and documentation that a set of two parallel GM sessions from the same source volumes (H1) to two other sets of volumes (H2 and H3) is just not supported. I have developed a new Idea and I could use some feedback. How does this sound? 1. A Metro Mirror within a single DS8k Where set H1 clones to H2. 2. Establish a second Global Mirror from H2 to the new DS8900F - H3 This is close to the Metro/Global Mirror scenario in the documentation. It just moves the H2 target from a 3rd DS8k into the H1 DS8k. There are potential pitfalls that need more research 1. Can H2 be Space Efficient volumes in a Internal Metro Mirror or do they have to be fully configured for space? 2. Can the H2 be both the target of a MM *and* the source of a GM relationship? 3. Does this expose us to buying additional capacity licenses for the Copy Services license? Fancy technology breeds fancy problems. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
