Hello,    The matrix is in the release notes.  I.e.   From the 9.0 release notes:   Replication PartnershipsReplication is supported only between certain firmware versions. Table 4. Replication Support – PS Series to Other PS Series shows whether replication is supported between any two partners running different firmware versions. (If you are running firmware earlier than version v6.0, contact your support provider.) Table 4. Replication Support – PS Series to Other PS SeriesFirmware on Primary GroupFirmware on Replication Partner v9.0  ->  v8.0.x, v8.1.x, v9.0.xv8.1  ->  v7.0.x, v7.1.x, v8.0.x, v8.1.x, v9.0.xv8.0  ->  v7.0.x, v7.1.x, v8.0.x, v8.1.x, v9.0.xv7.0,  -> v7.1 v6.0.x, v7.0.x, v7.1.x, v8.0.x, v8.1.xv6.0   -> v5.1.x, v5.2.x, v6.0.x, v7.0.x, v7.1.x  The new 6210XS will likely have v8.1 firmware on it.   You will need to upgrade the group receiving the new unit to v8.1.x anyway to maintain support.   You do want to upgrade the DR side as well.   When upgrading the firmware make sure there are no on going replication jobs.  It's best to let any running ones finish then pause replication.  Regards,  Don  
Hi  Is there any information about the firmware versions between replication primary and target? We found the matrix but v8 or v9 isn't included in that. Currently we plan to add new PS6210XS and make replication partnerships with PS6210E(v7.1.9) which has already replication partner with current storage group(PS 6210X v7.1.9). Do we have to upgrade the firmware of backup storage?  Thanks
Replication supported firmware