All members within a group have to run on the same FW level. Only for a short period of time a mixed config is allowed. If you really would like to add the PS6100 into your production group i suggest to update your production EQLs to 8.1.4 first.  Btw. one thing you should consider... mixing 10G and 1G units within a group or connecting to the same Host Cluster might not be the best idea. RegardsJoerg ps: for us the fw 9.x comes to early and we stay at 8.1.x for quiet some time
I have an existing PS6210 in production running PS Firmware 8.1.3. It is the sole member of the group, eqlgroup. We were able to acquire a PS6100, I spun it up and made it a member of its own group, eqltestgroup. The PS6110 is running PS Firmware 8.1.4 and I want to update it to 9.0.2 before adding it to the production group, eqlgroup (to save myself the task of updating the thing with production data on it). Can I upgrade PS6110's firmware to 9.0.2 and then add it to the production group? Will eqlgroup accept the PS6110 after the update? Or do I have to update the PS6210 to 8.1.4 (if I don't update the PS6110) or 9.0.2 (if I update the PS6110 to 9.0.2)? Honestly, I really want to test this myself but I don't want to do these kind of things on production stuff. Your advice is greatly appreciated,
Adding PS6110 v9.0.2 to a group with a sole member running 8.1.3