Extended file mapping cache for fast input-output
US8204871B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2010 |
| Grant date | Jun 19, 2012 |
| Priority date | — |
| Expiry date | Dec 30, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F16/172
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A file server has an extent cache of pointers to leaf-level indirect blocks containing file mapping metadata. The extent cache improves file access read and write performance by returning a mapping for the data blocks to be read or written without having to iterate through intermediate level indirect blocks of the file. In addition, the extent cache contains pointers to the leaf-level indirect blocks in the file system cache. Therefore, in most cases, the time spent looking up pointers in the extent cache is offset by a reduction in the time that would otherwise be spent in locating the leaf-level indirect blocks in the file system cache. In a preferred implementation, the extent cache has a first least recently used (LRU) list and cache entry allocation for production files, and a second LRU list and cache entry allocation for snapshot copies of the production files.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.