Data processing method for file status recovery includes providing a log file of atomic transactions that may span both volatile and non volatile memory
US5201044A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1990 |
| Grant date | Apr 6, 1993 |
| Priority date | — |
| Expiry date | Apr 16, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1471
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A data processing system includes both volatile and nonvolatile memories, user-inaccessible file control software and performs a method for recovering from a malfunction occurring during a file transaction that prevents accomplished microscopic transactions from being lost. The method comprises the steps of: providing a log file to maintain a record of file transactions which may span both the volatile and nonvolatile memories; recording in the portion of the log file in volatile memory, old and new data images which result during a file transaction; writing the old and new data images to a portion of the log file which is contained in nonvolatile memory, with the new data image being written after it is certain that the old data image is present in the nonvolatile memory; and in the event of a malfunction, employing the log file in nonvolatile memory to determine the status of a file transaction and rolling back the transaction in the event the malfunction occurred prior to its completion, and further assuring that all file system actions have actually occurred for transactions marked as completed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.