We have a system that's datasharing with the logon / connections to DB2 happening via the link list DSN that is shared across the LPARS
So member 1 goes to V11, member 2 stays on V10 on a different LPAR. So far so good. If we don't IPL the linklist modules are V10 which should keep connecting.
System 1 is IPL'd the link list now has the V11 mods. The shared dataset loaded to the link list can also be steplibed. If that were done and the jobs run against the V10 system would they fail? This would be utilities or TSO batch jobs.
System 2 is upgraded and the IPL / link list refresh follows everything is on 11.
I was thinking, would there be a case where someone tries to log on to the V10 system with the V11 libs and what would happen. Say System 2 crashes, comes up with the refreshed linklist while the DB2 member is still on V10.
I also read this https://www.ibm.com/support/knowledgecenter/en/SSEPEK_11.0.0/inst/src/tpc/db2z_mixedreleasedsgroup.html
It's clear we can go with the old version to the new. The other way around is probably a no but is that written down?