Balanced access to data volumes with redundant copies stored in data storage libraries
US6502165B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 1999 |
| Grant date | Dec 31, 2002 |
| Priority date | — |
| Expiry date | Dec 3, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data storage library system with a plurality of data storage libraries and at least one director accesses a redundant copy of an identifiable data volume, employing the idle time status of each library to balance the workload. The data volumes may be stored in cache storage and backing storage which have different levels of access speed. A director requests a data volume, and the library controller of each library determines its current idle time status, providing the idle time status to the requesting director when it provides a synchronization token directly associated with the requested data volume. The token indicates the update level and the access level of the data volume in the library. The director, upon determining from the tokens that at least two of the copies of the data volume are at the same fastest available access level, compares the provided idle time status of the libraries storing those copies, and accesses the data volume from the library having the greater idle time status.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.