摘要 |
A device and method for connection to a host and transferring data between the host and data storage assembly. The device is preferably a storage system which initializes a logical unit (LUN) in the storage assembly. A persistent memory stores a data representation of clean areas in the LUN. The storage system receives data to be written from the host to a destination area in the LUN, and determines if the destination area in the LUN is a clean area or a dirty area as indicated in the persistent memory. The storage system effects a snapshot copy of data from the destination area in the LUN to an archive storage device of the storage assembly only if the destination area is not entirely a clean area. Bandwidth is likewise reduced in LUN copy and reconstruction operations.
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