If you go to page 27 on the below support guide it gives specifics around the backward compatibility mode you will need to run in.  /A will run in legacy mode   [URL]
Hi,  I was in the discussion with my infrastructure folks this afternoon and checking for the possibility of SRDF/A between new VMAX flash array and VMAX Gen1 array and when I googled it unfortunately I couldn't  find any earlier discussion or document on this topic.  here is where I need your help, 1. First of all is it possible for the SRDF between the VMAX flash and VMAX gen1? without any major caveats.. 2. Has anyone successfully implemented this config in your environment? 3. If any document or discussion link is available please do share it.   Thanks DP
Possibility of SRDF/A between VMAX flash arrays and VMAX GEN1 (20K)