A designated storage system receives a request to store data in the local storage as a backup copy. The designated storage system requests a file system in the computer system to store the backup copy as a file in the local storage and maintains a record describing storage locations for each of the one or more sets of contiguous available file system data blocks. The storage system may transmit the record to a management computer configured to track which of the computer systems has stored the backup copy. The storage system then requests the file system to delete the file, whereupon the file system removes the file descriptor and frees the one or more file system data blocks in order to satisfy the deletion request but does not delete the data stored in the one or more file system data blocks.