NetWare File System
| Industry | Computer software, Network operating systems |
|---|---|
| Founded | November 3, 1983 |
| Founder | Raymond Noorda |
| Headquarters | Provo, Utah , United States |
| Products | NetWare, NetWare File System (NWFS), Novell Storage Services (NSS) |
In computing, the NetWare File System (NWFS) was a journaling, FAT-based file system specifically optimized for use within the Novell NetWare network operating system. It served as the exclusive file system for all storage volumes in NetWare versions 2.x through 4.x, and continued to be the default choice for the SYS: volume up to version 5.x. Novell engineered two distinct NWFS versions:
- The 16-bit NWFS 286 designed for NetWare 2.x
- The 32-bit NWFS 386 utilized from NetWare 3.x through 6.x
Starting with NetWare 5, Novell introduced Novell Storage Services (NSS) in 1998, which supplanted NWFS.
While Novell never officially disclosed the on-disk format of NWFS, former developers released a comprehensive open-source reimplementation in 2000 compatible with Windows, Linux, and DOS platforms. This project thoroughly documented all internal structures of the file system and was made available on GitHub and GitLab.
Notable technical details of the 32-bit NWFS include:
- Maximum file size: 4 GB
- Maximum volume capacity: 1 TB
- Maximum files per volume (single namespace): 2 million
- Maximum files per server: 16 million
- Maximum directory entries: 16 million
- Maximum volumes per server: 64; per partition: 8
- Maximum concurrently open files per server: 100,000
- Directory hierarchy depth supported up to 100 levels
- Support for ASCII double-byte character sets and extended attributes (up to 512)
- Capability of handling up to 10 data streams within a single file
- Multiple namespace compatibility including Windows Long Names (OS/2), Unix, and Apple Macintosh environments
- Features such as deleted file recovery, journaling via Novell Transaction Tracking System (TTS), and block suballocation introduced from NetWare version 4.x
To boost efficiency when managing large files, NWFS incorporated Turbo FAT technology.
The file system offered transparent compression functionality; however, this came at the expense of reduced file serving speed. Since each namespace requires its own directory entry, employing multiple namespaces proportionally decreases the total available directory entries.
The earlier 16-bit NWFS variant supported volume sizes up to 256 MB and included a dedicated API tailored for Macintosh client integration.
NWFS integrated RAID-like capabilities well before RAID became widespread on personal computers, featuring disk mirroring and duplexing. It also accommodated multi-segmented volumes and round-robin read operations, aligning with RAID 0 and RAID 1 functionalities.