You need to format the disk for rsnapshot to be able to use hard links. An external drive mounted via '''"smbfs"''' '''"FAT formatting "''', '''"NTFS"''', or '''"cifs"''' does not allow "hard links". It is not possible to create "snapshot-like" backups on FAT or NTFS formatted volumes, nor SMB/CIFS as these filesystems do not support this unfortunatelyhard-linking.