Hi Jenny, Your migration methodology is going to depend on your retention requirements.  That is, you'll have to determine at some point whether or not your organization requires that the files are retained based upon the atime of the file, or if it doesn't matter at all.     Create a SmartLock root directory.  Copy data to it with cp, rsync or SyncIQ.  When you have decided upon a retention date, you can then set it on the SmartLock root with isi worm modify.  Then you will have to commit your files to to SmartLock by removing write access from the ACLs of the files.  This can be done by setting the windows RO attribute (with Powershell or some other method), by removing w access via chmod or by turning autocommit on.    The important thing to remember is that the retention period of the file will depend on the atime of the file, unless you use the --override flag.  If you use the --override flag, the atime will be reset and the retention period will depend on the date that you copied the file to the SmartLock root. 
I notice isi worm create can only desinates an existing directory as a WORM root directory, but it must be empty.  I already have a directory with many files in it and now I need to turn on WORM, how can that be done?
Designates an existing non-empty directory as a WORM root directory