Systems and methods of data migration in snapshot operations
US7136974B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2003 |
| Grant date | Nov 14, 2006 |
| Priority date | — |
| Expiry date | Apr 7, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2201/82
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to snapshots of a data storage system including a host that communicates with a cache memory, source storage, target storage, and metadata, including a source storage for active data, a target storage to store migrated snapshot data, first metadata (e.g., bitmaps and log files with pointers) to indicate when and where the first snapshot data is in target storage, and second metadata (e.g., bitmaps and log files pointers) to indicate when and where the second snapshot data is in target storage where the first and second metadata locate the same snapshot data in the target storage. The invention maintains data consistency when reading metadata for snapshots into host memory, searching the metadata to identify snapshots that require original data to be destaged, destaging the original data to target storage, and updating the metadata to locate the original data and indicate completion of the target destage operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.