Patent ID: 7647525
Filing Date: 2010-01-12
Classification: G06F

Abstract:
1. A method of resuming triangular asynchronous replication operations between a primary group at a first data center, a synchronous backup group at a second data center, and an asynchronous backup group at a third data center, the method comprising: stopping work at a data storage device temporarily hosting the primary group at one of: the second data center and the third data center; configuring data mirroring relationships to provide for synchronous data mirroring from the data storage device at the first data center to a data storage device at the second data center; configuring data mirroring relationships to provide for an asynchronous data mirror from the data storage device at the first data center to a data storage device at the third data center, wherein writes begun at the first data center after a first time and before a second time are associated with a first chunk of data and writes begun after the second time are associated with a second chunk of data different from the first chunk of data and wherein, after completion of all writes associated with the first chunk of data, data for writes associated with the first chunk of data is transferred to the third data center and, in response to receiving a message separate from the first and second chunks of data indicating the transfer of the first chunk of data is complete from the first data center to the third data center, the data storage device at the third data center stores the data writes associated with the first chunk of data; and resuming work at the first data center.