Professional File System
| PFS | |
|---|---|
| Manufacturer | Michiel Pelt |
| Full name | Professional File System |
| Initial release | 1995 (AmigaOS) |
| Partition identifier | 'PFS \ 1', 'muAF', 'AFS \ 1' (Amiga RDB ) |
| Maximum values | |
| Length of the file name | 107 characters |
| File system size | 137 GiB |
| Allowed characters in the file name | Everything but zero, '/' and ':' |
| properties | |
| Date range | Jan. 1, 1978 - 2157 |
| File rights management | Amiga Permissions, Multiuser Permissions |
| Transparent compression | No |
| Transparent encryption | No |
| Supporting operating systems | AmigaOS, MorphOS |
The Professional File System is a file system that was originally developed commercially for the Amiga in 1995 by Michiel Pelt . It is available today on Aminet under a BSD license . Due to the simplicity of the design, PFS performs well and is a compatible successor to Ami-Filesafe.
Divided into two main areas, the metadata is stored at the beginning, consisting of a root block and a generic series of blocks. The rest is another coherent general arrangement of blocks where the actual data is stored.
The metadata is stored in a tree structure of individual blocks. The entire data structure is stored in the metadata, so that the data part only contains "real" data. The metadata describe the location of the data (in files) with the associated addresses of blocks, which makes the metadata very compact.
When a metadata update occurs, the system copies the metadata block to be changed to a reassigned block in the metadata section with the changes made, and then recursively changes the metadata in the original block in the same manner. If the root block has to be changed too, this leads to an "atomic" metadata update.
The degree of fragmentation of the files is comparatively small.
As the first Amiga file system in which the concept of the "recycle bin" was natively integrated on the file system level, it keeps the most recently deleted files in a hidden directory on the (root) hard drive. PFS V5.3 was developed in C and a small part of assembler code.