US Patent 10331350 Capacity determination for content-based storage

A computer program product, system, and method for visiting each node of a snapshot tree within a content-based storage system having a plurality of volumes and/or snapshots; for each node, scanning an address-to-hash (A2H) table to calculate one or more resource usage metrics, wherein the A2H tables map logical I/O addresses to chunk hashes; and determining, based on the resource usage metrics, an amount of memory and/or disk capacity that would be freed by deleting one or more of the volumes and/or snapshots.