US Patent 10459648 Change rate estimation

File measurements are computed and stored in persistent memory of a deduplicated storage system as files are written or on demand, where the file measurements are used to estimate storage requirements for storing a subset of files. The file measurements are accumulated into an initial measurement at a first point in time and a final measurement at a second point in time to obtain an estimate of any change in a quantity of unique segments required to store the subset of files in the deduplicated storage system between the first and second points in time. Future storage requirements can be estimated based on a computed rate of change in the amount of storage required to store the subset of files between the first and second points in time.