Definition
File allocation table (FAT) is a file system architecture developed by Microsoft for managing and organizing files on storage devices.
It employs a table to monitor clusters across the storage volume, mapping out how they are grouped to form files and directories.
How FAT Systems Operate
- The FAT system generates an index table listing all files stored on the device or system.
- The index table includes an entry corresponding to each data cluster.
- The entries include the number of the next cluster, an end-of-file (EOF) marker, indicators for unused disk space, and markers for other reserved areas on the drive.
- The operating system checks the cluster number of each file segment in sequence until it encounters the file’s end.
Technical Details
- FATs are on the disk’s first sector (disk sector 0).
- FAT has three main versions: FAT12, FAT16, and FAT32.
- File allocation tables support volume sizes of up to 4GB.
- FAT lacks adequate file system security.
Common Uses for FAT Systems
- USB flash drives
- Memory cards
- Portable devices
- Digital cameras