Failover to backup site in connection with triangular asynchronous replication

摘要

Handling failure of a primary group at a first data center that is part of plurality of data centers providing triangular asynchronous replication, includes creating a data mirroring relationship between at least one storage volume at a second data center having a synchronous backup group that is part of the plurality of data centers and at least one storage volume at a third data center having an asynchronous backup group that is part of the plurality of data centers and resuming work at the second data center. Handling failure of a primary group at a first data center may also include synchronizing the at least one storage volume at the second data center with the at least one storage volume at the third data center prior to resuming work at the second data center.

主权项

1. A method of handling failure of a primary group at a first data center that is part of plurality of data centers providing triangular asynchronous replication, the method comprising:
creating a data mirroring relationship between at least one storage volume at a second data center having a synchronous backup group that is part of the plurality of data centers and at least one storage volume at a third data center having an asynchronous backup group that is part of the plurality of data centers, wherein data writes to a local storage volume at the primary group begun after a first time and before a second time are associated with a first chunk of data and data writes to the local storage volume at the primary group begun after the second time are associated with a second chunk of data and wherein the at least one storage volume at the third data center stores data from the first chunk in response to receipt of a message from the primary group indicating that all data from the first chunk has been transmitted to the third data center; maintaining failure recovery data that indicates data of the first and second chunks of data that has not yet been completely transferred to the third data center; synchronizing the second and third data centers, wherein the failure recovery data indicates 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 and wherein synchronizing the second and third data centers includes discarding data corresponding to a particular chunk that has been received at the third data center if only some of the data for the particular chunk has been received at the third data center; and after synchronizing the second and third data centers, resuming work at one of: the second data center and the third data center.