Patent ID: 8788768
Filing Date: 2014-07-22
Classification: G06F

Abstract:
1. A computer program product for maintaining copies of data in a first storage system at a first site and a second storage system at a second site, the computer program product comprising at least one non-transitory computer readable storage device including first program code and second program code, wherein the first program code is executed in a first server at the first site and the second program code is executed at a second server at the second site, wherein the first program code and second program code execute to perform operations, the operations comprising: maintaining, by the first program code, a mirror copy relationship between the first storage system and the second storage system to mirror data at the first storage system to the second storage system, wherein the first and second sites connect over a network; performing, by the first program code, a first point-in-time copy operation from the first storage system to a first storage system copy, wherein the data for the first storage system copy is consistent as of the determined point-in-time, wherein the point-in-time copy operation is completed upon creating a data structure indicating data for the first storage system copy as located at the first storage system or the first storage system copy; determining, by the first program code, a timestamp, wherein the first storage system copy is consistent as of the determined timestamp; transmitting, by the first program code, a command to the second server to create a point-in-time copy of the second storage system that indicates the determined timestamp; processing, by the second program code, mirror data transferred from the first server as part of the mirror copy relationship to determine whether a timestamp associated with the mirror data applied to the second storage system is equal to the timestamp indicated in the command in response to the command; and performing, by the second program code, a second point-in-time copy operation, in response to determining that the timestamp of the mirror data is equal to the timestamp indicated in the command from the mirror data to create the second point-in-time copy.