Hello,   You can't have supported and unsupported/EOL arrays in the same group.   Nor do you want to use it for replication.  Since if you did have a problem, support will be limited in what they can do with that unsupported HW.   re: Migrating the PS4000.  I would suggest that you create a new pool put the 4210 in that pool.  Create the RAIDset and make sure both interfaces are enabled.   Then move the PS4210 into the same pool as the PS4000.   This will cause the space to be redistributed to the new array.     If you want to minimize any possible performance impact, wait until the space is rebalanced.   Then move the PS4000 to the temp pool.   This will leave all the data on the PS4210.   Once it's in the temp pool, you can use the "delete member" option to remove it from the group.   There will be future firmware updates for the PS4000.   Regards, 
We have a ps4000 (sata, 16x1tb) that's running out of maintenance in may without ability to renew. The ps4000 is a target for replication of windows/hyper-v volumes from a ps6100x and runs some hyper-v volumes with developer/test virtual machines. We bought a new ps4210x to replace the old one. It would be run on 1gbit for at least the next year. The best way to move the data is to update the firmware on the ps4000 to the same the 4210x has and then join the 4210x to the ps4000 group? Is there a checklist what exactly is to do for moving the data from one member to the other?  We are unsure what to do with the old system. We thinking about buying one or two replacement disks in advance and using it for some more time. Using it as a replication target and hosting some not important virtual machines. Would you suggest running both systems in the same group? Should we use two pools for volume placement or would you just let the firmware load balance the data? Both systems have raid6. What is with support, if we run both systems in the same group? Would we still get software support for the whole group or would Dell say one of the member does not have support anymore and we could not help you at all? As I understand the firmware release notes, the 7.x will the last major version for ps5xxx. Our ps4000 from 2010 will have some more time with firmware updates? 
Running old and new array in same group?