International Business Machines Corporation
Using mirror path statistics in recalling extents to a primary storage system and a secondary storage system from a third storage system

Abstract:

Provided are a computer program product, system, and method for using mirror path statistics in recalling extents to a primary storage system and a secondary storage system from a third storage system, A recall request is received to recall extents from the third storage that were migrated from the primary storage or the secondary storage to the third storage. A determination is made as to whether mirror paths used to migrate extents from the primary storage to the secondary storage exceed a degradation criteria. Commands are sent to cause the recall extents to be recalled from the third storage to both the primary storage and the secondary storage in response to determining that the mirror paths exceed the degradation criteria.