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WAN Deduplication: Getting More by Sending Less
Data deduplication is one of the most significant technologies to impact the storage community in recent years. By identifying redundant data segments and storing only a single instance of information, this technology dramatically reduces storage space and allows more data to be protected over time.
WAN deduplication (also called "disk based data reduction") works by deploying acceleration appliances in each enterprise location (i.e. on both ends of a WAN connection). The WAN acceleration appliances inspect IP traffic in real-time and store a local instance of information in an application independent data store at the appropriate enterprise location. The local instance is transparently populated based on day-to-day usage, containing a subset of the enterprises working data set that is most relevant to each location. Each instance of information is stored only once per location, enabling an appropriately sized WAN acceleration appliance to hold weeks or months worth of data.
WAN acceleration appliances equipped with deduplication technology examine outbound packets to see if a match exists in the local instance at the destination location. If a match exists, then the repetitive information is not sent across the WAN and instructions are sent to deliver the data locally. If the data has been modified, only the delta is transmitted across the WAN, maximizing bandwidth utilization and application performance.