in the system 39 s physical drives pds a system manager 107 allows users to create vvs and export them make visible and accessible to hosts as logical unit numbers luns the destination storage system 104 includes a low level migration engine 112 also known as the region mover at the ld level that copies and mirrors data between sets of lds mapped to physical disks pds the ld mirroring process duplicates any host writes to both locations ensuring data consistency in one example a migration manager 108 on a host computer 110 uses migration engine 112 in a method to migrate volumes from source storage system 102 to destination storage system 104 in another example migration manager 108 uses migration engine 112 in methods to convert a fully provisioned vv fpvv on storage system 104 to a thinly provisioned vv tpvv and vice versa the migration manager 108 may be implemented with executable instructions for a processor in host computer 110 the executable instructions may be stored in a non transitory computer readable medium such as a hard disk drive a solid state drive or another type of nonvolatile memory the host computer 110 is coupled to destination storage system 104 the destination storage system 104 includes a full mesh backplane that joins multiple controller nodes to form a cache coherent cluster in one example each controller node may contain processing complexes memories and network interface cards for data movement and control functions e g an asic and associated memory for data movement and central processing units and associated memory for control functions controller nodes are paired.