Cache/disk subsystem with file number for recovery of cached data
US4598357A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1983 |
| Grant date | Jul 1, 1986 |
| Priority date | — |
| Expiry date | Jan 25, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a cache/disk sybsystem employing the post-store technique, each file is assigned a file number. The file number is an address in a directory on a disk, this address containing pointers to the physical disk space assigned to that file. During normal operation of the subsystem a device number and address are utilized to transfer written-to segments of data from a cache store to a disk. If a failure occurs which prevents the cache-to-disk transfer of a segment of data, a storage control unit forms a status word and a sense message. The sense message includes the file number and information defining the fault. A host processor is then notified that the status word is available. The host processor obtains the status word and indexes into a status action branch table. The branch table entry directs the host processor to issue a Sense I/O command to obtain from the storage control unit the sense message identifying the fault. The executive program of the host processor may subsequently utilize the sense message, which also includes the file number, to assign new disk space at which the segment of data may be recorded. The segment of data which could not be written to the disk is first …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.