If you move the placeholders then all the data will be recalled and then the placeholders will be reacreated so if you have a lot of data then you really do not want to recall all of your data.
There is a data mover utility in version 7 to move placeholders correctly without recalling all of the data. In version 7 this is only supported on NTFS partitions and not netapp filers.
So I would recommend upgrading to V7 SP2 which is the latest version and then reading up on the FSA data mover utility,