Delegated reference count base file versioning
US8032498B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2009 |
| Grant date | Oct 4, 2011 |
| Priority date | — |
| Expiry date | Mar 27, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/128
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A snapshot copy facility maintains information indicating block ownership and sharing between successive versions by delegating block reference counts to parent-child relationships between the file system blocks, as indicated by block pointers in inodes and indirect blocks. When a child block becomes shared between a parent block of the production file and a parent block of a snapshot copy, the delegated reference count is split among the parent blocks. This method is compatible with a conventional data de-duplication facility, and avoids a need to update block reference counts in block metadata of child blocks of a shared indirect block upon splitting the shared indirect block when writing to a production file.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.