Preferential caching of uncopied logical volumes in an IBM peer-to-peer virtual tape server
US6745212B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 2001 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | Mar 7, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99955
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is a system, method, and an article of manufacture for preferentially keeping an uncopied data set in one of two storage devices in a peer-to-peer environment when data needs to be removed from the storage devices. Each time a data set is modified or newly created, flags are used to denote whether the data set needs to be copied from one storage device to the other. The preferred embodiments modify the timestamp for each uncopied data set by adding a period of time, and thus give preference to the uncopied data set when the data from the storage device is removed based on the least recently used as denoted by timestamp of each data set. Once the data set is copied, the timestamp is set back to normal by subtracting the same period of time added on when the data set was flagged as needing to be copied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.