You won't have a problem as long as the target drive is the same model # as the source. And JMFS will squawk if the target drive is too small. Hook up the source and target drives, run JMFS. It will look for a drive with the MFS O.S. on them. If it only shows one drive you should be good to go. IF it shows 2 drives, flip a coin. NOOOOO. The best way to find out is write down the drive serial numbers. eXit out of the JMFS menu and type this command "hdparm -I /dev/sda" (thats an uppercase I), after the screen stops scrolling use <shift> <page up> <page down> to scroll the screen output. Scroll up the screen and at the beginng you will find the drive serial number, write down which S/N is sda. Do it again using "hdparm -I /dev/sdb" and write down which S/N is sdb. You don't need to reboot to get back to the guide, just type "/root/guide.sh" and go from there. When you select the copy function the /dev/sda or dev/sdb will be on the same line as the drive info. AND be prepared..... it takes 18 hours to copy the 2TB to a 2TB..... I know.