Triangular asynchronous replication

摘要

Storing recovery data includes providing chunks of data to a remote destination, where each chunk of data represents data written before a first time and after a second time and where the second time for one of the particular chunks corresponds to a first time for a subsequent one of the particular chunks, providing synchronous data to a local destination, and providing an indicator to the local destination in connection with creation of a new chunk of data for storage at the remote destination. The local destination may maintain a plurality of maps, where each of the maps associates synchronous data being provided thereto with a specific chunk of data. In response to receiving an indicator in connection with creation of a new chunk of data, the local destination may point to a new map. There may be two maps or more than two maps.

主权项

1. A method for a remote storage device to facilitate storing recovery data, the method comprising:
receiving an indicator corresponding to failure of at least some of a first set of data to be synchronously transferred from a local storage device to an intermediate storage device, the first set of data corresponding to writes to the local storage device; receiving a second set of data asynchronously transferred from the local storage device to the remote storage device; and maintaining at least one map at the remote storage device that indicates differences between portions of the first set of data and portions of the second set of data.