How can I change an NTFS Volume UUID?
Usually NTFS volumes don't contain UUIDs. The visible UUID in diskutil is derived from the NTFS Volume Serial Number.

Get the disk identifier of your backup disk and the volume:

diskutil list


Unmount the external disk:

diskutil umountDisk /dev/disk1


Copy the NTFS superblock:

sudo dd if=/dev/disk1s4 of=~/Desktop/superblock bs=512 count=1


Change the mod bits:

sudo chmod 777 ~/Desktop/superblock 


Create a backup of the superblock (just in case!):

cp ~/Desktop/superblock ~/Desktop/superblock.backup


Modify the file superblock with HexFiend:



The NTFS volume serial number is highlighted in violet (eight bytes beginning at offset 72 or 0x48). Modify at least one byte. After saving the file check the size which should still be 512 Bytes.

Write back the superblock:

sudo dd if=~/Desktop/superblock of=/dev/disk1s4 bs=512 count=1


Reboot your Mac and verify the new UUID of disk1s4.