Incremental disk backup system for a dynamically mapped data storage subsystem
US5210866A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1990 |
| Grant date | May 11, 1993 |
| Priority date | — |
| Expiry date | Sep 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2201/815
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The parallel disk drive array data storage subsystem dynamically maps between virtual and physical data storage devices and schedules the writing of data to these devices. The 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. A mapping table is maintained to identify portions of these redundancy groups which contain newly written or modified virtual track instances. These marked virtual track instances are written to backup medium as a background process and the mapping table is updated to clear the flags that identify these virtual track instances as having been modified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.