Disk fragmentation reduction using file allocation tables
US5890169A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1998 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Jun 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99957
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A combined file allocation table file system (CFAT file system) uses two or more FAT file systems with different cluster sizes to form a single user visible FAT file system to reduce disk fragmentation. The FAT file system having the largest cluster size is used to store all of the other small FAT file systems as files with holes. The clusters of the small FAT file systems thus do not occupy disk space until they are allocated. Files containing user data are stored in one or many of the large and small FAT file systems to achieve optimal storage. More clusters are available for storing files with sizes that are smaller than the size of one large cluster. A CFAT file system includes: a large file allocation table for large clusters, a file allocation table extension to provide holes within the CFAT file system, and any number of small file allocation tables providing a variety of small cluster sizes. A file is stored in clusters as large as possible except for the last cluster which is stored in only as large a cluster size as is needed. Other allocation strategies are possible. The Small FAT file systems are contained within regular files of the Large FAT file system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.