NetVault FastRecover's patented two-stage delta reduction technology

As the Product Manager for Quest's NetVault FastRecover, I am regularly asked how FastRecover is able to protect the large amounts of rapidly changing data sent from clients.


The Answer: The continuous data protection (CDP) solution uses a patented two-stage delta reduction process.


The best way to explain how this solution works is to break it down.


First Stage of NetVault FastRecover Delta Reduction.
Unlike traditional CDP solutions that transfer every changed byte or block written by an application to the filesystem, NetVault FastRecover employs an intelligent filter driver design. This design only uploads new and/or changed data that has not already been sent to the FastRecover server. During the protection process, our driver requests signatures from the NetVault FastRecover server. The driver then uses those signatures to identify data that is new and/or changed and uploads it. This process is known as “First-Stage Delta Reduction.”


By performing First-Stage Delta Reduction, FastRecover’s filter driver only uploads a small amount of data. For example, most desktop applications write an entire document when a user inserts just one byte of data into that document. If a document is 1 MB, and 1 byte is inserted, using the traditional CDP method, the whole document would be archived. This is very inefficient. FastRecover’s intelligent filter driver will upload a much smaller amount of data, with the actual changed data uploaded between 100 bytes to 1 KB in size (depending on signature width).


Second Stage of NetVault FastRecover Delta Reduction.
As mentioned above, FastRecover’s filter driver only sends new and/or changed bytes and blocks from client to server. Once the data is transferred, FastRecover will then compare the data it already has with the most recent data archived. Once the comparison is complete only new data will be kept. This process is known as “Second-Stage Delta Reduction.”


NetVault FastRecover’s patented two-stage delta reduction technology allows the use of minimal bandwidth and storage resources while still maintaining down to the second restore capabilities.