Two-pass defragmentation of compressed hard disk data with a single data rewrite
US5574907A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1994 |
| Grant date | Nov 12, 1996 |
| Priority date | — |
| Expiry date | Nov 30, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/401
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for defragmenting compressed file data stored on a disk. The method includes a first pass in which the FAT and MDFAT entries for each file stored on the disk are rearranged into adjacent clusters, but in which no movement of the compressed file data occurs. The method includes a second pass in which the actual compressed file data is rearranged on the disk in accordance with the FAT and MDFAT entries. A reference point is identified within the disk storage space such that no compressed file data will be stored beyond the reference point after the second pass is completed. During the rearrangement of data during the second pass, compressed file data is temporarily relocated beyond the reference point if possible. During all movements of compressed file data, the method transfers as much data as can be stored within the space to which the data is to be moved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.