Patent ID: 9268658
Filing Date: 2016-02-23
CPC Classification: G06F

Claim Text:
1. A method of handling failure of a primary group at a first data center having a synchronous mirroring relationship with a second data center and having an asynchronous mirroring relationship with a third data center by transferring data in chunks, the method comprising: maintaining failure recovery data that indicates data that has not yet been asynchronously transferred to the third data center; synchronizing the second and third data centers according to the failure recovery data indicating whether to synchronize the second and third data centers by providing initial data from the second data center to the third data center or by providing initial data from the third data center to the second data center, wherein any partial chunk of data received at the third data center is discarded; and after synchronizing the second and third data centers, resuming work at one of: the second data center and the third data center.