Deduplication of data stored in a copy volume

摘要

A source volume and a copy volume are stored, where the copy volume contains data that has been modified by writes to the source volume. In response to a write to a particular location and resource volume, a deduplication data structure is checked to determine whether the copy volume contains data that is the same as data in the particular location. In response to determining from the deduplication data structure that a copy volume contains the same data as the data in the particular location, a reference to the first location of the copy volume storing the same data is added instead of repeating storing of the data of the particular location in the copy volume.

主权项

1. A method comprising:
storing a source volume on physical storage media; storing a copy volume that contains data that has been modified by writes to the source volume; in response to a write to a particular location in the source volume, checking a deduplication data structure to determine whether the copy volume contains data that is the same as data in the particular location; in response to determining from the deduplication data structure that the copy volume contains the same data as the data in the particular location, adding a reference to a first location of the copy volume storing the same data instead of repeating storing of the data of the particular location in the copy volume; and in response to determining from the deduplication data structure that the copy volume does not contain the same data as the data in the particular location of the source volume, adding an entry to the deduplication data structure, where the added entry contains a signature corresponding to the data of the particular location of the source volume, and where the added entry further includes an address of a location of the copy volume that contains the data of the particular location of the source volume.