Synchronization storage solution after an offline event

Abstract

Disclosed are systems and methods of synchronization between a source and a target. The synchronization relationship can be quickly and easily be created for disaster recovery, real-time backup and failover, thereby ensuring that data on the source is fully-protected at an off-site location or on another server or VM, for example, at another data center, a different building or elsewhere in the cloud. Common snapshots available on both the source and target can act as common recovery points. The common recovery points can be used to locate the most recent snapshot in common, between the source and target, to enable a delta sync of all subsequently written data at the source to the target after an offline event.

What is claimed is: 
     
         1 . A method for synchronizing a first server and a second server after an offline event at the first server, the first server is a source and the second server is a target, the method comprising:
 determining a common snapshot between the first server and the second server;   promoting the second server to the source, wherein the second server receives new write requests subsequent to the offline event and registers the new write requests in a clone of the common snapshot, thereby generating an updated common snapshot clone;   in response to the first server coming back online, identifying un-replicated data that was written to the first server prior to the offline event but was not written to the common snapshot;   replicating the un-replicated data from the first server to the second server; and   replicating the updated common snapshot clone from the second server to the first server, such that the second server is in a synchronized replication relationship with the firs server.