Storage system with flexible scanning supporting storage volume addition and/or recovery in asynchronous replication

A method comprising:

• generating a current snapshot set for a consistency group comprising a plurality of storage volumes subject to replication from a source storage system to a target storage system;
• scheduling a differential scan of the current snapshot set relative to a previous snapshot set generated for the consistency group;
• for each snapshot tree of a first group of one or more snapshot trees of the current snapshot set, identifying a non-root node of that snapshot tree as a start node;
• for each snapshot tree of a second group of one or more other snapshot trees of the current snapshot set, identifying a root node of that snapshot tree as a start node;
• performing an instance of the differential scan for each of the one or more snapshot trees of the first group utilizing its identified non-root node as the start node;
• and
• performing an instance of a full scan for each of the one or more snapshot trees of the second group utilizing its identified root node as the start node;
• wherein the method is implemented by at least one processing device comprising a processor coupled to a memory.

A computer program product comprising a non-transitory processor-readable storage medium having stored therein program code of one or more software programs, wherein the program code when executed by at least one processing device causes said at least one processing device:

• to generate a current snapshot set for a consistency group comprising a plurality of storage volumes subject to replication from a source storage system to a target storage system;
• to schedule a differential scan of the current snapshot set relative to a previous snapshot set generated for the consistency group;
• for each snapshot tree of a first group of one or more snapshot trees of the current snapshot set, to identify a non-root node of that snapshot tree as a start node;
• for each snapshot tree of a second group of one or more other snapshot trees of the current snapshot set, to identify a root node of that snapshot tree as a start node;
• to perform an instance of the differential scan for each of the one or more snapshot trees of the first group utilizing its identified non-root node as the start node;
• and
• to perform an instance of a full scan for each of the one or more snapshot trees of the second group utilizing its identified root node as the start node.