Does anybody know why Ntbackup would backup a folder with the name SharedHardlinkData? I am testing a filter driver that implements HSM-like functionality (redirects the reads for a given file) and the files I place my reparse point on generate this activity when backed up via ntbackup. The files have a reparse point and are made sparse (with all data removed from the primary stream). They also have 2 named streams added to them. I have tried making another file sparse and adding a reparse point via fsutil and this file does not generate this activity. The value given for the reparse tag does not seem to make any difference.
Ntbackup wants to backup data in this folder even if my driver is not running (although it skips the files there if it is not loaded). I have to suspect that something about the files causes NT to look at this folder but I have not been able to find out what it is. Googling for SharedHardlinkData produces very few hits and none that have any clues as to what is going on.