Content-based replication of data between storage units

Abstract

Methods, systems, and computer programs are presented for replicating data across storage systems. One method includes an operation for transferring a snapshot of a volume from an upstream array to a downstream array. The method further includes an operation for comparing an upstream snapshot checksum of the snapshot in the upstream array with a downstream snapshot checksum of the snapshot in the downstream array. When the upstream snapshot checksum is different from the downstream snapshot checksum, a plurality of chunks in the snapshot are defined. Further, for each chunk in the snapshot, a comparison is made of an upstream chunk checksum calculated by the upstream array with a downstream chunk checksum calculated by the downstream array. When the upstream chunk checksum is different from the downstream chunk checksum then the data of the chunk is sent from the upstream array to the downstream array.

Description

CLAIM OF PRIORITY[0001]This application claims priority from U.S. Provisional Patent Application No. 62 / 084,395, filed Nov. 25, 2014, entitled “Content-Based Replication of Data Between Storage Units,” and from U.S. Provisional Patent Application No. 62 / 084,403, filed Nov. 25, 2014, entitled “Content-Based Replication of Data in Scale Out System.” These provisional applications are herein incorporated by reference.CROSS REFERENCE TO RELATED APPLICATIONS[0002]This application is related by subject matter to U.S. patent application Ser. No. ______ (Attorney Docket No. NIMSP112) filed on the same day as the instant application and entitled “Content-Based Replication of Data in Scale Out System”, which is incorporated herein by reference.BACKGROUND[0003]1. Field of the Invention[0004]The present embodiments relate to methods, systems, and programs for replicating data in a networked storage system.[0005]2. Description of the Related Art[0006]Network storage, also referred to as network ...

AI Technical Summary

Problems solved by technology

However, when transferring large volumes of data, there could be some glitches during the transfer / replication process, and some of the data may be improperly transferred.

It may be very expensive resource wise to retransfer all the data, because it may take a large amount of processor and network resources that may impact the ongoing operation of the data service.

If a change is detected between snapshots being replicated, it may be very expensive to transmit over the network large amounts of data if only a small portion of the data has changed.

Further yet, if a common base snapshot is lost, resending all the data may be very expensive.

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