AtvCloner 0.1.4b Update
This AtvCloner update addresses the dreaded error:
newfs_hfs: /dev/rdisk2s4: partition size not a multiple of 4K.
accompanied by a failure to properly format the media partition error which is typically seen on drives > 500GB (though may be experienced on smaller drives depending on firmware). You will notice a checkbox next to the “Prepare New Drive” Button for “Large Drive Formatting” ( sue me, I didn’t know what else to call it ). This uses an alternate method of drive formatting which cures my problem child and has worked on a couple other drives with this issue. The caveat is that it creates a media partition approximately 300 mb smaller than the standard AtvCloner method due to diskutil creating 128 mb of free space before and after the media partition. On the other hand it works ( so far ) for those problem drives. I will try to elaborate more later. You can get AtvCloner 0.1.4b here.