NetApp, Inc.
NON-DISRPUTIVE TRANSITIONING BETWEEN REPLICATION SCHEMES

Abstract:

A technique transitions data blocks of volumes served by storage nodes of a storage cluster from an old data protection scheme (DPS) to a new DPS in a non-disruptive manner. Slice services of the storage nodes forward the data blocks associated with write requests to the block services for storage on storage devices of the nodes. Mapping of volume logical block addresses to block identifiers are contained in slice files, wherein there is a single slice file for each volume. To transition a volume between the old and new DPSs, the slice service tags the data blocks with the new DPS when forwarding new write requests to the block services. In accordance with a background transitioning process, the slice service also retrieves every data block referenced by the to slice file and then resends the data to the block service with the new DPS.