Single-instance store, or SIS, is an architecture designed to maintain duplicate files with a minimum of disk, cache, and backup media overhead. Single-instance store backup, or SIS backup, is an API that backup applications call to access the SIS architecture.
Further MS SIS information can be found on the following links:
http://msdn.microsoft.com/en-gb/library/windows/desktop/aa362538(v=vs.85).aspx
http://technet.microsoft.com/en-us/library/dd573308(v=ws.10).aspx
We currently do not support this MS feature at the moment and have raised an Enhancement Request with Engineering already (Bug 3896). Please check the NetVault Backup Release Notes on future versions.
