Defrag 3tb external HDD

Is it ok to defrag a 3 tb external drive.  I ask because I know this gpt format is different.  I use defraggler.com.

I don’t see any problems defragmenting the drive…

Right. All disk defragmenters in Windows use the Windows API, so to speak.

This means that the defragger program will tell Windows where to put the file. Then Windows itself goes ahead and moves the file. And the process continues.

http://www.piriform.com/defraggler/features/safe-and-secure