Konrad Raynes Davda & Victor LLP
Source-target relations mapping
A data preservation function is provided which, in one embodiment, includes mapping in a plurality of maps for a target storage device, map extent ranges of each map, to corresponding target extent ranges of storage locations on the target storage device. Usage of a particular map extent range by a relationship between a source extent range of storage locations on a source storage device containing data to be preserved in the source extent range, and the target extent range mapped to the map particular extent range, may be indicated by the map. In another aspect, in response to receipt of a data preservation command, a data preservation operation is performed including determining whether a map indicates availability of a map extent range mapped to the identified target extent range. Upon determining that a particular map indicates availability of a map extent range mapped to the identified target extent range, a relationship between the identified source extent range and the identified target extent range is established. In yet another aspect, upon determining that no map indicates availability of a map extent range mapped to the identified target extent range, establishing of a relationship between the identified source extent range and the identified target extent range may be delayed until it is determined that a particular map indicates availability of a map extent range mapped to the identified target extent range. Other features and aspects may be realized, depending upon the particular application.
INTERNATIONAL BUSINESS MACHINES CORPORATION
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Carol S. Lokesh M. Theresa M. Michael T.
Mellgren Gupta Brown Benhase