Data file storage management system for snapshot copy operations
US6038639A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1997 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Sep 9, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2201/84
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present data file storage management system for snapshot copy operations maintains a two level mapping table which enables the data files to be copied using the snapshot copy process and only having to update a single corresponding mapping table entry when the physical location of the data file is changed. The snapshot copy updates to the contents of the first level of the two level mapping table are stored on the backend data storage devices to provide a record of the snapshot copy operation which can be used to recover the correct contents of the mapping table. This record of the snapshot copy operations remains valid even though the physical location of a copied data file instance is subsequently changed. Furthermore, the physical storage space holding the updated portions of the first level of the two level mapping table can be managed using techniques like those used to manage the physical storage space holding data file instances. Mapping table updates resulting from the snapshot copy operation are delayed until all mapping table updates resulting from earlier data file write operations have been completed and any attempt to update the mapping table to reflect data writte…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.