Patent ID: 7603581

Claim:
A method, comprising: establishing a first copy relationship between first and second storage locations in a first storage system and second storage system, respectively, wherein updates to the first storage locations are copied to the second storage locations; establishing a second copy relationship between the first storage locations in the first copy relationship and third storage locations in a third storage system, wherein updates to the first storage locations are indicated in a first bitmap; establishing a suspended third copy relationship between the second storage locations in the first copy relationship and the third storage locations, wherein updates to the second storage locations are indicated in a second bitmap; copying updates from the first or second storage locations to the third storage locations, wherein the first or second bitmap is capable of being used to determine updates for the first or second storage locations to copy to the third storage locations; providing a toggle command to the first storage system to clear the first bitmap in response to transferring the updates indicated in the first bitmap from the first storage locations to the third storage locations according to the second copy relationship; setting a flag on the toggle command provided to the first storage system instructing the first storage system to propagate the toggle command to the second storage system; and propagating the toggle command to the second storage system in response to receiving the toggle command to clear the second bitmap for the suspended third copy relationship.