In some circumstances, a destination drive may not support hardlinks. Please try the following:
1. Reformatting the drive as Mac OS Extended (Journaled) if allowed by the system to support hardlinks. Please keep in mind that drives formatted as Mac OS Extended (Journaled) cannot be read natively by Windows computers.
2. Create a Disk Image and use it as your destination.
To do this:
- Launch Disk Utility located in Applications > Utilities
- Choose File > New > Blank Disk Image.
- Type a name for the disk image, and choose where you want to save it.
- In the Name field, enter the name for the disk that appears when you open the disk image.
- Choose the size of the disk image from the Size pop-up menu.
- Choose the format for the disk from the Format pop-up menu: Mac OS Extended (Journaled)
The disadvantages of using a disk image:
- They use a little more space than copying files directly.
- Backups on disk images are a little bit slower (the time needed to mount / unmount the disk image).
- If the disk image is corrupted, the whole backup may be unreadable.
- It does support all Mac OS X metadata (permissions, extended attributes, …).
- It does support hardlinks.