US Patent 9952767 Consistency group management

A consistency group is used as a basic unit of data management of storage containers served by a storage input/output (I/O) stack executing on one or more nodes of a cluster. The storage container may be a LUN embodied as parent volume (active volume), a snapshot (represented as an independent volume embodied as read-only copy of the active volume), and a clone (represented as another independent volume embodied as a read-write copy (clone) of the active volume). A consistency group (CG) is a set (i.e., collection) of objects, e.g., LUNs or other CGs (nested CG), which may be managed and operated upon collectively by an administrative command via a Storage Area Network administration layer (SAL) of the storage I/O stack. The SAL may interact with one or more layers of the storage I/O stack to (i) create a clone of a set of object members of the CG; (ii) create one or more snapshots of the set of object members of the CG; (iii) restore the set of object members of the CG from a group of CG snapshots; (iv) replicate the set of object members of the CG as a single entity; and (v) delete a CG and a nested CG according to specific semantics.