Multilevel, hierarchical, dynamically mapped data storage subsystem
November 19, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesSystem for facilitating the copying back of data in disc and tape units of a memory hierarchial system Virtual storage system and method Method and apparatus for grouping asynchronous recording operations Optimizing volume mounts in a multidrive environment Fast write operations Method of managing data in a data storage hierarchy and a data storage hierarchy therefor with removal of the least recently mounted medium Patent #: 4987533 InventorAssigneeApplicationNo. 615329 filed on 11/19/1990US Classes:711/114, Arrayed (e.g., RAIDs)711/113CachingExaminersPrimary: Bowler, Alyssa H.Attorney, Agent or FirmInternational ClassesG06F 013/00G06F 012/08 AbstractThe disk drive array data storage subsystem functions as a conventional large form factor disk drive memory, using an array of redundancy groups, each containing N+M disk drives. The data storage subsystem does not modify data stored in a redundancy group but simply writes the modified data as a new record in available memory space on another redundancy group. The original data is flagged as obsolete. Virtual tracks that are least used are migrated as part of a free space collection process to low access cylinders, which are, in turn, migrated to secondary media, such as magnetic tape. The migration process is either periodic or demand driven to automatically archive little used data records. | |
