Outboard file cache system
US5809527A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1993 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Dec 23, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/312
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system and method are described for caching files of data in a cache which is beyond the input/output boundary of a host. A host references a file with file access commands containing a logical file-identifier and a logical offset into the file. An outboard file cache coupled to the input/output section of the host receives the file access commands. The outboard file cache is transparent to users who program the host. Generation of input/output channel programs and mapping the data referenced to a physical address in secondary storage are eliminated when the referenced data is present in the cache. A file descriptor table in the outboard file cache identifies the logical portions of the logical files which are present in the cache. If the data referenced by the logical file-identifier and logical offset in a file access command is present in the outboard file cache, the data is transferred from the outboard file cache to the host memory. Otherwise, a miss status is returned to the host, and the host stages data from secondary storage to the outboard file cache. The outboard file cache further includes a lock table for storing file locks which inhibit access to selected files. In …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.