Isilon has made it easy to migrate data from NetApp filers to Isilon clusters. They made a utility called isi_vol_copy that copies files including its metadata and its ACL (access control list) information via NDMP protocol. The utility is run on the Isilon command line interface. There is no need to use a separate host that executes migration tools such as robocopy, which may be slower and more difficult to manage.
isi_vol_copy is versatile enough to do a full baseline copy of data and perform updates of the deltas on a daily basis using the incremental switch, until the day of the cutover. Since Isilon is BSD-based, the incremental copy jobs can be run via crontabs.
The load can also be distributed by running the isi_vol_copy utility on multiple nodes on the Isilon cluster.
The syntax of the command is:
isi_vol_copy <source_filer>:<directory> -full|incr -sa username:password <destination_directory_on_Isilon>