Hard links
When you archive files that are hard-linked, the backup-archive client archives each instance of the linked file.
For example, if you archive two files that are hard-linked, the client archives the file data twice.
When you retrieve hard-linked files, the client reestablishes the links. For example, if you had a hard-linked pair of files, and only one of the hard-linked files is on your workstation, when you retrieve both files, they are hard-linked. The only exception to this procedure occurs if you archive two files that are hard-linked and then break the connection between them on your workstation. If you retrieve the two files from the server, the client respects the current file system and does not retrieve the hard link.
Tip: If you do not archive and retrieve all files that
are hard-linked at the same time, problems can occur. To ensure that
hard-linked files remain synchronized, archive all hard links at the
same time and retrieve those same files together.