Data replication snapshots for persistent storage using operation numbers

A computer-implemented method, comprising:

• maintaining a master copy and a slave copy of a data volume, the master copy including data for a plurality of operations having respective sequential operation numbers, the data for the plurality of the operations being replicated to the slave copy;
• generating a snapshot of the master copy, the snapshot being assigned a next operation number in an operation number sequence, the snapshot including snapshot data for operation numbers between an operation number of a prior snapshot and an operation number of the snapshot, the snapshot being replicated to the slave copy;
• writing the snapshot data, as well as the operation number and metadata for the snapshot, to the persistent storage;
• and
• while writing the snapshot data to persistent storage, causing subsequent I/O operations to be assigned respective operation numbers in sequence and processed by the master copy.

A system, comprising:

• at least one processor;
• a block-based storage system;
• and
• memory including instructions that, when executed by the at least one processor, cause the at least one processor to:
• store a master copy and a slave copy of a data volume in the block-based storage system, the master copy including data for a plurality of operations having respective sequential operation numbers, the data for the sequential operations numbers being replicated to the slave copy;
• generate a snapshot of the master copy, the snapshot being assigned a next operation number in an operation number sequence, the snapshot including snapshot data for operation numbers between an operation number of a prior snapshot and an operation number of the snapshot, the snapshot being replicated to the slave copy using the operation number of the snapshot;
• write the snapshot data, as well as the operation number and metadata for the snapshot, to the persistent storage;
• and
• while writing the snapshot data to persistent storage, cause subsequent I/O operations to be assigned respective operation numbers in sequence and processed by the master copy.