Organization of read-write snapshot copies in a data storage system
US7035881B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 2003 |
| Grant date | Apr 25, 2006 |
| Priority date | — |
| Expiry date | May 13, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99955
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A file server maintains a series of read-only snapshot copies of a production file system. A read-write snapshot copy is created based on a selected read-only snapshot copy by maintaining a set of save volume blocks of new data of the read-write snapshot copy. A block of new data is written to the read-write snapshot copy by allocating a save volume block and writing to the save volume block. A specified block is read from the read-write snapshot copy by checking whether there is a respective save volume block allocated to the specified block, and if so, reading from the respective save volume block, and if not, reading from the read-only snapshot copy upon which the read-write snapshot copy is based. The read-write snapshot copy can be refreshed with a specified read-only snapshot copy. The production file can be restored with a specified read-write snapshot copy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.