Patent ID: 8195636

Claim:
A method of determining an amount of storage space that would be reclaimed in a storage system as a result of deletion of a plurality of logical containers of data, the method comprising: identifying, by the storage system, a plurality of logical containers of data to be deleted from a dataset of a storage system, each of the plurality of logical containers of data including references to one or more data blocks stored in the dataset, an indication of the plurality of logical containers of data having been input into the storage system by a user for determining a total amount of physical storage space that would be freed up in the storage system upon deletion of the plurality of logical containers of data; calculating, by the storage system, a total number of references made to each individual data block by the identified plurality of logical containers of data; and determining the total amount of storage space that would be reclaimed through deletion of the identified plurality of logical containers of data, by: identifying, by the storage system, a total number of individual data blocks, among all data blocks referenced by the identified plurality of logical containers of data for which the total number of references made by the identified logical containers of data matches an overall reference count associated with such individual data blocks, wherein the overall reference count associated with a given data block is an overall number of references made to the given data block by all logical containers of data stored in the dataset; calculating a total amount of storage space utilized within the storage system by the identified total number of individual data blocks that match the overall reference count; and determining the calculated overall amount of storage space as the total amount of storage space that would be reclaimed.