The Professional File System is a

filesystem In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is Computer data storage, stored and retrieved. Without a file system, data placed in a storage me ...

originally developed commercially for the

Amiga Amiga is a family of personal computers introduced by Commodore International, Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and sign ...

, now distributed on

Aminet Aminet is the world's largest archive of Amiga-related software and files. Aminet was originally hosted by several universities' FTP sites, and is now available on CD-ROM and on the web. According to Aminet, as of 3 September 2022, it has 83930 pa ...

with a 4-clause

BSD license BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lice ...

. It is a compatible successor of AmiFileSafe (AFS), with an emphasis on added reliability and speed compared to standard Amiga filesystems. It also features multi-user abilities like the older MuFS. The device is split into two main areas. At the beginning of the device is the metadata section, which consists of a root block, and a generic array of blocks that can be allocated to store metadata. The rest of the device is another contiguous generic array of blocks that can be allocated to store data. The metadata section usually uses a few percent of the device, depending on the size of the device. The metadata is stored as a tree of single blocks in the metadata section. The entire directory structure is recorded in the metadata, so the data section purely contains data from files. The metadata describes the location of data in files with extents of blocks, which makes the metadata quite compact. When a metadata update occurs, the system looks at the block containing the metadata to be changed, and copies it to a newly allocated block from the metadata section, with the change made, then it recursively changes the metadata in the block that points to that block in the same way. This way, eventually the root block needs to be changed, which causes the atomic metadata update. The filesystem is reasonably good at keeping files unfragmented, although there is a defragmentation tool available which will work on an online filesystem. It was the first filesystem to introduce the concept of the

Recycle Bin A recycling bin (or recycle bin) is a container used to hold recyclables before they are taken to recycling centers. Recycling bins exist in various sizes for use inside and outside homes, offices, and large public facilities. Separate con ...

natively at filesystem-level to the Amiga, holding the last few deleted files in a hidden directory on the disk root. PFS version 5.3 was developed in C and a small portion of assembly code by Michiel Pelt.

References

External links

Official repositoryPFS3 All-In-One
{{File systems Disk file systems Amiga software AmigaOS MorphOS software AROS software Free system software

See also

References

External links