RSYNC: This UNIX utility is used for NFS migrations. As technology advanced, storage vendors provided a way to perform these migrations using internal tools. Some of the tools were developed for disaster recovery while others were developed explicitly for data migration. Two examples include:
VNX Replicator: This tool can replicate from Celerra/VNX to another Celerra/VNX array. Isi_vol_copy: The isi_vol_copy utility from Isilon uses NDMP streams to copy data from a NetApp array to the Isilon array. Eventually EMC added isi_vol_copy_vnx that allowed NDMP- based copy from VNX to the Isilon.