A FalconStor spokesperson contacted Techworld wishing to correct assertions made by Sepaton CTO, Miki Sandorfi. Contrary to his statement that Falconstor de-duplicates backup data in band (and therefore slows down backup speed), a FalconStor spokesperson said: "FalconStor de-dupes after the backup is complete (out of band)."

Contrary to Sepaton's statement that "FalconStor has taken a mixed approach with its SIR Technology. It uses a content-aware type approach to identify common objects and then uses hashing to find the redundancies. Because hashing is fundamentally part of finding redundancies, the algorithm is classified as hash-based." the spokesperson said: "We are content-aware."

Sepaton's CTO said: "FalconStor indicates that it supports clustering. It is not clear what size data set can be supported with a dual node cluster. Their technology is designed as an add-on technology requiring entirely separate hardware and storage and is not an integrated part of their VTL (virtual tape library) solution." and: "FalconStor highlights an ability to cluster its SIR (single instance repository) engines. Note that its de-duplication occurs inside an entirely separate environment then its VTL - requiring separate servers and storage that must be managed separately."

"FalconStor highlights its ability to add up to two SIR engines to provide additional de-duplication performance. Of course, since each is a separate managed entity this adds substantially to system management overhead."

Au contraire, Falconstor's spokeperson says: "(Our de-duplication) is fully integrated with the IPStor platform and VTL. The two separate boxes are simply a testing and architecture decision for our enterprise customers. We are addressing the needs of some of the Fortune 10 companies FIRST."

He agrees that: "FalconStor de-dupe is CPU intensive, whereas VTL is I/O intensive.

He adds: "We want multiple VTL’s and SIR’s to share the same pool of storage and, yes, that means we can dynamically allocate storage between SIR’s and between the VTL’s and SIR.

In fact FalconStor: "has the one box model in the lab and is using it for evaluation units right now with customers. It is just a matter of engineering."

FalconStor strongly disputes Sepaton's assertion that it has performance problems with backup when carrying out de-duplication. It denies that its de-duplication technology isn't integrated with its VTL and it says that its SIR and VTL products are integrated.

Finally: "Any discussion of hashing is digging around on the floor when there are much larger issues to discuss around the whole approach to data protection and backup."