Using logical block addresses with generation numbers as data fingerprints for network deduplication

摘要

The technique introduced here involves using a block address and a corresponding generation number as a “fingerprint” to uniquely identify a sequence of data within a given storage domain. Each block address has an associated generation number which indicates the number of times that data at that block address has been modified. This technique can be employed, for example, to determine whether a given storage server already has the data, and to avoid sending the data to that storage server over a network if it already has the data. It can also be employed to maintain cache coherency among multiple storage nodes.

主权项

1. A method, comprising:
receiving, at a destination device, a write request identifying a source block address and a generation number, wherein a source device stores data associated with the write request at the source block address, the generation number indicating a number of times that data at the source block address has been modified; determining whether the destination device already has a data block that matches the source block address and the generation number; and processing, at the destination device, the write request by using the data block that matches the source block address and the generation number, without receiving the data associated with the write request from the source device, when it is determined that the destination device already has the data block that matches the source block address and the generation number.