Running: NBU 5.0 MP6

I have a fairly large LUN on Linux (~200 GB) being backed up to disk.
The DSU is has a 2GB fragment size.  I restored approximate 3GB and it
works, but the behavior is strange.  It will restore some amount of the
files then it continues to scan through the fragments (the GUI reports
that data is still being restored--though it isn't) until it reaches the
remainder of the files within the image and restores them.

The end result is the same-- 3GB are restored successfully, but the GUI
reports that over 100GB was restored-- and the time it takes to restore
the 3GB is what it would take to restore 100.  Is this normal behavior?
I don't think I'm doing anything incorrect, but is there a way to make
the restore more efficient?  Is there a fragment size that would improve
this?  Ideas are welcome.

Thanks in advance,
Justin King