Global data deduplication is a method of preventing redundant data when backing up data to multiple deduplication devices. This situation may involve backing up to more than one target deduplication appliance or, in the case of source deduplication, backing up to multiple backup nodes that are. themselves, backing up multiple clients.
With global deduplication, when data is sent from one node to another, the second node recognizes that the first node already has a copy of the data, and does not make an additional copy.
Global data deduplication makes the data deduplication process more effective and increases the data deduplication ratio (the ratio of protected capacity to the actual physical capacity stored), which helps to reduce the required capacity of disk or tapes systems used to store backup data.