You can replicate as you have described.  Depending on the host OS it maybe easier to do at the host level.   I.e. with VMware ESX you can move VMs live using Storage vMotion.  
Hi,   What's the best practice to move a volume from a PS4100 to another PS6100 The two PS are not in the same group. Today we have a PS5000XV which replicate on the PS4100. The administrator have create 2 volumes on the PS4100 (because there is not enough space on the PS5000XV). We will replace the PS5000XV with a new PS6100XV and we want to move the volume from the PS4100 to the new PS6100. What's easier way to do this with the minimum downtime on this volume? I think that the best is to create a replica of the 2 volume from the PS4100 to the new PS6100, disconnect the volume from the PS4100 and set online the volume on the PS6100. correct?? Thanks  
Best practice to move a volume