HPFS (High Performance File System) is the file system introduced with IBM's OS/2 Version 1.2. HPFS is noted for handling large files (2 gigabytes) across multiple hard disk volumes (addressable up to 2 terabytes) and long file names (up to 256 bytes). HPFS was designed to get around several limitations at the time in MS-DOS, among them its eight-character name restriction. HPFS uses a centrally-located root directory and B-tree lookup to speed access. HPFS can coexist with the MS-DOS file system, File Allocation Table (FAT), or run independently.
Among the benefits of HPFS:
- Contiguous storage of extended attributes (without the EA DATA.SF file used by FAT)
- Resistance to file fragmentation
- Small cluster size
- Support for larger file storage devices (up to 512 GB)
- Speedier disk operation
Among the drawbacks:
- Requires more system memory
- HPFS partitions are not visible to MS-DOS, so if you need to boot from a floppy disk, it could be inconvenient.
- Native DOS needs a special utility (Partition Magic from PowerQuest) to access a HPFS partition