Patent ID: 9158471
Filing Date: 2015-10-13
Classification: G06F

Abstract:
1. A method for copying data from a first storage to a second storage and a third storage, comprising: providing a point-in-time copy relationship to copy tracks as of a point-in-time in the first storage to a second storage; providing a mirror copy relationship to copy data in the second storage to the third storage; determining a track in the first storage to transfer to the second storage as part of the point-in-time copy relationship; determining a stride of tracks including a target track; staging the stride of tracks including the target track from the first storage to a cache according to the point-in-time copy relationship; destaging the staged stride from the cache to the second storage; transferring the stride in the cache to the third storage as part of the mirror copy relationship; and demoting the stride of tracks in the cache in response to destaging the stride of the tracks in the cache to the second storage and transferring the stride of tracks in the cache to the third storage.