Snapshot facility allowing preservation of chronological views on block drives
US7055010B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 2003 |
| Grant date | May 30, 2006 |
| Priority date | — |
| Expiry date | Nov 29, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99955
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for efficiently maintaining snapshot instances. To maintain the state of snapshot instances, the snapshot copies the data needed to be protected into free space on the same volume. In order to identify whether a block is free, a snapshot record is created for each block on a volume to record write operations on the block. With these snapshot records, the allocation status of blocks on a volume can quickly be identified. Free space allocation is then accomplished by allocating free space via the file-system provided interface and identifying it with snapshot records. With this mechanism, snapshot software can allocate free space to store snapshot metadata and “copy-to-write” data dynamically.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.