List of file systems

The following lists identify, characterize, and link to more thorough information on computer file systems.

Many older operating systems support only their one "native" file system, which does not bear any name apart from the name of the operating system itself.

Disk file systems

Disk file systems are usually block-oriented. Files in a block-oriented file system are sequences of blocks, often featuring fully random-access read, write, and modify operations.

  • ADFS – Acorn's Advanced Disc filing system, successor to DFS.
  • AdvFS – Advanced File System, designed by Digital Equipment Corporation for their Digital UNIX (now Tru64 UNIX) operating system.
  • APFS – Apple File System is a next-generation file system for Apple products.
  • AthFS – AtheOS File System, a 64-bit journaled filesystem now used by Syllable. Also called AFS.
  • BFS – the Boot File System used on System V release 4.0 and UnixWare.
  • BFS – the Be File System used on BeOS, occasionally misnamed as BeFS. Open source implementation called OpenBFS is used by the Haiku operating system.
  • Btrfs – is a copy-on-write file system for Linux announced by Oracle in 2007 and published under the GNU General Public License (GPL).
  • CFS – The Cluster File System from Veritas, a Symantec company. It is the parallel access version of VxFS.
  • CP/M file system — Native filesystem used in the CP/M (Control Program for Microcomputers) operating system which was first released in 1974.
  • DOS 3.x – Original floppy operating system and file system developed for the Apple II
  • Extent File System (EFS) – an older block filing system under IRIX.
  • ext – Extended file system, designed for Linux systems
  • ext2 – Second extended file system, designed for Linux systems.
  • ext3 – A journaled form of ext2.
  • ext4 – A follow up for ext3 and also a journaled filesystem with support for extents.
  • ext3cow – A versioning file system form of ext3.
  • FAT – File Allocation Table, initially used on DOS and Microsoft Windows and now widely used for portable USB storage and some other devices; FAT12, FAT16 and FAT32 for 12-, 16- and 32-bit table depths.
  • FFS (Amiga) – Fast File System, used on Amiga systems. This FS has evolved over time. Now counts FFS1, FFS Intl, FFS DCache, FFS2.
  • FFS – Fast File System, used on* BSD systems
  • Fossil – Plan 9 from Bell Labs snapshot archival file system.
  • Files-11 – OpenVMS file system; also used on some PDP-11 systems; supports record-oriented files
  • Flex machine file system
  • HFS – Hierarchical File System in z/OS; not to be confused with Apple's HFS. HFS is still supported but IBM's stated direction is zFS.
  • HFS – Hierarchical File System, in use until HFS+ was introduced on Mac OS 8.1. Also known as Mac OS Standard format. Successor to Macintosh File System (MFS) & predecessor to HFS+; not to be confused with IBM's HFS provided with z/OS
  • HFS+ – Updated version of Apple’s HFS, Hierarchical File System, supported on Mac OS 8.1 & above, including macOS. Supports file system journaling, enabling recovery of data after a system crash. Also referred to as 'Mac OS Extended format or HFS Plus
  • HPFS – High Performance File System, used on OS/2
  • HTFS – High Throughput Filesystem, used on SCO OpenServer
  • ISO 9660 – Used on CD-ROM and DVD-ROM discs (Rock Ridge and Joliet are extensions to this)
  • JFS – IBM Journaling file system, provided in Linux, OS/2, and AIX. Supports extents.
  • LFS – 4.4BSD implementation of a log-structured file system
  • MFS – Macintosh File System, used on early Classic Mac OS systems. Succeeded by Hierarchical File System (HFS).
  • Next3 – A form of ext3 with snapshots support.[1]
  • MFS – TiVo's Media File System, a proprietary fault tolerant format used on TiVo hard drives for real time recording from live TV.
  • Minix file system – Used on Minix systems
  • NILFS – Linux implementation of a log-structured file system
  • NTFS – (New Technology File System) Used on Microsoft's Windows NT-based operating systems
  • NetWare File System – The original NetWare 2.x–5.x file system, used optionally by later versions.
  • NSS – Novell Storage Services. This is a new 64-bit journaling file system using a balanced tree algorithm. Used in NetWare versions 5.0-up and recently ported to Linux.
  • OneFS – One File System. This is a fully journaled, distributed file system used by Isilon. OneFS uses FlexProtect and Reed-Solomon encodings to support up to four simultaneous disk failures.
  • OFS – Old File System, on Amiga. Good for floppies, but fairly useless on hard drives.
  • OS-9 file system
  • PFS – and PFS2, PFS3, etc. Technically interesting file system available for the Amiga, performs very well under a lot of circumstances. Very simple and elegant.
  • ProDOS – Operating system and file system successor to DOS 3.x, for use on Apple’s computers prior to the Macintosh & Lisa computers, the Apple series, including the IIgs
  • Qnx4fs – File system that is used in QNX version 4 and 6.
  • ReFS (Resilient File System) – New file system by Microsoft that is built on the foundations of NTFS (but cannot boot, has a default cluster size of 64 KB and does not support compression) and is intended to be used with the Windows Server 2012 operating system.
  • ReiserFS – File system that uses journaling
  • Reiser4 – File system that uses journaling, newest version of ReiserFS
  • Reliance – Datalight's transactional file system for high reliability applications
  • Reliance Nitro – Tree-based transactional file system developed for high-performance embedded systems, from Datalight
  • RFS – Native filesystem for RTEMS[2]
  • SkyFS – Developed for SkyOS to replace BFS as the operating system's main file system. It is based on BFS, but contains many new features.
  • SFS – Smart File System, journaling file system available for the Amiga platforms.
  • Soup (Apple) – the "file system" for Apple Newton Platform, structured as a shallow database
  • Tux3 – An experimental versioning file system intended as a replacement for ext3
  • UDF – Packet-based file system for WORM/RW media such as CD-RW and DVD, now supports hard drives and flash memory as well.
  • UFS – Unix File System, used on Solaris and older BSD systems
  • UFS2 – Unix File System, used on newer BSD systems
  • VxFS Veritas file system, first commercial journaling file system; HP-UX, Solaris, Linux, AIX, UnixWare
  • XFS – Used on SGI IRIX and Linux systems
  • zFS – z/OS Distributed File Service zSeries File System; not to be confused with other file systems named zFS or ZFS.
  • ZFS – a combined file system and logical volume manager designed by Sun Microsystems

File systems with built-in fault-tolerance

These file systems have built-in checksumming and either mirroring or parity for extra redundancy on one or several block devices:

File systems optimized for flash memory, solid state media

Solid state media, such as flash memory, are similar to disks in their interfaces, but have different problems. At low level, they require special handling such as wear leveling and different error detection and correction algorithms. Typically a device such as a solid-state drive handles such operations internally and therefore a regular file system can be used. However, for certain specialized installations (embedded systems, industrial applications) a file system optimized for plain flash memory is advantageous.

  • exFAT – Microsoft proprietary system intended for flash cards (see also XCFiles, an exFAT implementation for Wind River VxWorks and other embedded operating systems).
  • ExtremeFFS – internal filesystem for SSDs.
  • F2FS – Flash-Friendly File System. An open source Linux file system introduced by Samsung in 2012.[3]
  • FFS2 (presumably preceded by FFS1), one of the earliest flash file systems. Developed and patented by Microsoft in the early 1990s.[4]
  • JFFS – original log structured Linux file system for NOR flash media.
  • JFFS2 – successor of JFFS, for NAND and NOR flash.
  • LSFS – a Log-structured file system with writable snapshots and inline data deduplication created by StarWind Software. Uses DRAM and flash to cache spinning disks.
  • LogFS – intended to replace JFFS2, better scalability. No longer under active development.[5]
  • NILFS – a log-structured file system for Linux with continuous snapshots.
  • Non-Volatile File System – the "non-volatile file system" for flash memory introduced by Palm, Inc.
  • NOVA – the "non-volatile memory accelerated" file system for persistent main memory.
  • OneFS – a filesystem utilized by Isilon. It supports selective placement of meta-data directly onto flash SSD.
  • Segger Microcontroller Systems emFile – filesystem for deeply embedded applications which supports both NAND and NOR flash. Wear leveling, fast read and write, and very low RAM usage.
  • SPIFFS – SPI Flash File System, a wear-leveling filesystem intended for small NOR flash devices.
  • TFAT – a transactional version of the FAT filesystem.
  • TrueFFS – internal file system for SSDs, implementing error correction, bad block re-mapping and wear-leveling.
  • UBIFS – successor of JFFS2, optimized to utilize non-volatile DRAM.
  • Write Anywhere File Layout (WAFL) – an internal file system utilized by NetApp within their DataONTAP OS, originally optimized to use non-volatile DRAM. WAFL uses RAID-DP to protect against multiple disk failures and NVRAM for transaction log replays.
  • YAFFS – a log-structured file system designed for NAND flash, but also used with NOR flash.
  • ZFS – allows placing write-ahead log (ZIL) on flash, and using flash as a second-level read cache (L2ARC).

Record-oriented file systems

In record-oriented file systems files are stored as a collection of records. They are typically associated with mainframe and minicomputer operating systems. Programs read and write whole records, rather than bytes or arbitrary byte ranges, and can seek to a record boundary but not within records. The more sophisticated record-oriented file systems have more in common with simple databases than with other file systems.

Shared-disk file systems

Shared-disk file systems (also called shared-storage file systems, SAN file system, Clustered file system or even cluster file systems) are primarily used in a storage area network where all nodes directly access the block storage where the file system is located. This makes it possible for nodes to fail without affecting access to the file system from the other nodes. Shared-disk file systems are normally used in a high-availability cluster together with storage on hardware RAID. Shared-disk file systems normally do not scale over 64 or 128 nodes.

Shared-disk file systems may be symmetric where metadata is distributed among the nodes or asymmetric with centralized metadata servers.

Distributed file systems

Distributed file systems are also called network file systems. Many implementations have been made, they are location dependent and they have access control lists (ACLs), unless otherwise stated below.

Distributed fault-tolerant file systems

Distributed fault-tolerant replication of data between nodes (between servers or servers/clients) for high availability and offline (disconnected) operation.

  • Coda from Carnegie Mellon University focuses on bandwidth-adaptive operation (including disconnected operation) using a client-side cache for mobile computing. It is a descendant of AFS-2. It is available for Linux under the GPL.
  • Distributed File System (Dfs) from Microsoft focuses on location transparency and high availability. Available for Windows under a proprietary software license.
  • InterMezzo from Cluster File Systems uses synchronization over HTTP. Available for Linux under GPL but no longer in development since the developers are working on Lustre.
  • Lizardfs a networking, distributed file system based on MooseFS
  • Moose File System (MooseFS) is a networking, distributed file system. It spreads data over several physical locations (servers), which are visible to a user as one resource. Works on Linux, FreeBSD, NetBSD, OpenSolaris and macOS. Master server and chunkservers can also run on Solaris and Windows with Cygwin.
  • Scality is a distributed fault-tolerant filesystem.
  • Tahoe-LAFS is an open source secure, decentralized, fault-tolerant filesystem utilizing encryption as the basis for a least-authority replicated design.
  • A FAT12 and FAT16 (and FAT32) extension to support automatic file distribution across nodes with extra attributes like local, mirror on update, mirror on close, compound on update, compound on close in IBM 4680 OS and Toshiba 4690 OS. The distribution attributes are stored on a file-by-file basis in special entries in the directory table.[9][10]

Distributed parallel file systems

Distributed parallel file systems stripe data over multiple servers for high performance. They are normally used in high-performance computing (HPC).

Some of the distributed parallel file systems use object storage device (OSD) (In Lustre called OST) for chunks of data together with centralized metadata servers.

Distributed parallel fault-tolerant file systems

Distributed file systems, which also are parallel and fault tolerant, stripe and replicate data over multiple servers for high performance and to maintain data integrity. Even if a server fails no data is lost. The file systems are used in both high-performance computing (HPC) and high-availability clusters.

All file systems listed here focus on high availability, scalability and high performance unless otherwise stated below.

Name By License OS Description
BeeGFS (formerly FhGFS) Fraunhofer Society Open-source (GPLv2 & BeeGFS EULA) Linux A free to use file system with optional professional support, designed for easy usage and high performance, used on some of the fastest computer clusters in the world. BeeGFS allows replication of storage volumes with automatic failover and self-healing.
Ceph Inktank Storage, a company acquired by Red Hat LGPL Linux kernel A massively scalable object store. CephFS was merged into the Linux kernel in 2010. Ceph's foundation is the reliable autonomic distributed object store (RADOS), which provides object storage via programmatic interface and S3 or Swift REST APIs, block storage to QEMU/KVM/Linux hosts, and POSIX filesystem storage which can be mounted by Linux kernel and FUSE clients.
Chiron FS is a fuse-based, transparent replication file system, layering on an existing file system and implementing at the file system level what RAID 1 does at the device level. A notably convenient consequence is the possibility of picking single target directories, without the need of replicating entire partitions. (The project has no visible activity after 2008, a status request in Oct. 2009 in the chironfs-forum is unanswered)
CloudStore Kosmix Apache License 2.0 Google File System workalike. Replaced by Quantcast File System (QFS)
dCache DESY and others A write once filesystem, accessible via various protocols
General Parallel File System (GPFS) IBM proprietary AIX, Linux and Windows Support replication between attached block storage. Symmetric or asymmetric (configurable)
Gfarm file system Asia Pacific Grid X11 License Linux, macOS, FreeBSD, NetBSD and Solaris Uses OpenLDAP or PostgreSQL for metadata and FUSE or LUFS for mounting
GlusterFS Gluster, a company acquired by Red Hat GNU General Public License v3 Linux, NetBSD, FreeBSD, OpenSolaris A general purpose distributed file system for scalable storage. It aggregates various storage bricks over Infiniband RDMA or TCP/IP interconnect into one large parallel network file system. GlusterFS is the main component in Red Hat Storage Server.
Google File System (GFS) Google internal software Focus on fault tolerance, high throughput and scalability
Hadoop Distributed File System Apache Software Foundation Apache License 2.0 Cross-platform Open source GoogleFS clone
IBRIX Fusion IBRIX proprietary software
Infinit Infinit International, Inc proprietary cross-platform A POSIX-compliant file system for both local area network and wide area networks. Infinit replicates blocks of data between the various storage resources composing the infrastructure (being local or through cloud API) in order to guarantee data reliability (durability and availability) through Byzantine fault tolerance and data rebalancing (i.e. self healing).
LizardFS Skytechnology GPL cross-platform An open source, highly available POSIX-compliant file system that supports Windows clients.
Lustre originally developed by Cluster File Systems and currently supported by OpenSFS GPL Linux A POSIX-compliant, high-performance filesystem used on a majority of systems in the Top-500 list of HPC systems. Lustre has high availability via storage failover.
MapR FS MapR Proprietary Linux Highly scalable, POSIX compliant, fault tolerant, read/write filesystem with a distributed, fault tolerant metadata service. It provides an HDFS and NFS interface to clients as well as a noSQL table interface and Apache Kafka compatible messaging system
MooseFS Core Technology GPLv2/proprietary[11] Linux/NetBSD/FreeBSD/macOS/OpenSolaris MooseFS is a fault tolerant, highly available and high performance scale-out network distributed file system. It spreads data over several physical commodity x86 servers, which are visible to the user as one namespace. For standard file operations MooseFS acts like any other Unix-like file systems
ObjectiveFS Objective Security Corporation proprietary Linux, macOS POSIX-compliant shared distributed filesystem. Uses object store as a backend. Runs on AWS S3, GCS and object store devices.
OneFS distributed file system Isilon FreeBSD BSD based OS on dedicated Intel based hardware, serving NFS v3 and SMB/CIFS to Windows, macOS, Linux and other UNIX clients under a proprietary software
RozoFS Rozo Systems GNU GPLv2 Linux A POSIX DFS focused on fault-tolerance and high-performance, based on the Mojette erasure code to reduce significantly the amount of redundancy (compared to plain replication).
Scality Scality ring Proprietary software Linux A POSIX file system focused on high availability and performance. Also provides S3/rest/nfs interfaces.
Tahoe-LAFS Tahoe-LAFS Software Foundation GNU GPL 2+ and other[12] Windows, Linux, macOS secure, decentralized, fault-tolerant, peer-to-peer distributed data store and distributed file system
XtreemFS Contrail E.U. project, the German MoSGrid project and the German project "First We Take Berlin" open-source (BSD) Linux, Solaris, macOS, Windows cross-platform file system for wide area networks. It replicates the data for fault tolerance and caches metadata and data to improve performance over high-latency links. SSL and X.509 certificates support makes XtreemFS usable over public networks. It also supports Striping for usage in a cluster.

In development:

Peer-to-peer file systems

Some of these may be called cooperative storage cloud.

  • Cleversafe uses Cauchy Reed-Solomon information dispersal algorithms to separate data into unrecognizable slices and distribute them, via secure Internet connections, to multiple storage locations.
  • Infinit is a peer-to-peer file system that can be deployed on-premise or over a set of storage resources of different nature: local disk, NAS and even cloud-based resources.
  • Scality is a distributed filesystem using the Chord peer-to-peer protocol.
  • IPFS InterPlanetary File System is p2p, worldwide distributed content-addressable, file-system.

Special-purpose file systems

  • aufs an enhanced version of UnionFS stackable unification file system
  • AXFS (small footprint compressed read-only, with XIP)
  • Barracuda WebDAV plug-in. Secure Network File Server for embedded devices.
  • Boot File System is used on UnixWare to store files necessary for its boot process.
  • cdfs (reading and writing of CDs)
  • Compact Disc File System (reading and writing of CDs; experimental)
  • cfs (caching)
  • Cramfs (small footprint compressed read-only)
  • Davfs2 (WebDAV)
  • Freenet – Decentralized, censorship-resistant
  • FTPFS (ftp access)
  • GmailFS (Google Mail File System)
  • lnfs (long names)
  • LTFS (Linear Tape File System for LTO and Enterprise tape)
  • MVFS – MultiVersion File System, proprietary, used by Rational ClearCase.
  • romfs
  • SquashFS (compressed read-only)
  • UMSDOS, UVFAT – FAT file systems extended to store permissions and metadata (and in the case of UVFAT, VFAT long file names), used for Linux
  • UnionFS – stackable unification file system, which can appear to merge the contents of several directories (branches), while keeping their physical content separate
  • Venti – Plan 9 de-duplicated storage used by Fossil.
  • WBFS – Wii Backup FileSystem

Pseudo- and virtual file systems

  • devfs – Virtual file system in Unix-like operating systems for managing devices on-the-fly
  • debugfs –Virtual file system in Linux for accessing and controlling kernel debugging.
  • procfs – Pseudo-file system, used to access kernel information about processes
  • tmpfs – in-memory temporary file system (on Linux platforms).
  • specfs – Special File System for device files
  • sysfs – Virtual file system in Unix-like operating systems holding information about buses, devices, firmware, filesystems, etc.
  • wikifs – a server application for Plan 9's virtual, wiki, file system
  • WinFS – Windows Future Storage, was planned as the successor to NTFS for Windows Vista.

Encrypted file systems

File system interfaces

These are not really file systems; they allow access to file systems from an operating system standpoint.

  • FUSE (file system in userspace, like LUFS but better maintained)
  • LUFS (Linux userland file system – seems to be abandoned in favour of FUSE)
  • VFS Virtual Filesystem

See also

References

  1. ↑ Corbet, Jonathan. "The Next3 filesystem". LWN.
  2. ↑ "RTEMS File System". Retrieved 20 April 2013.
  3. ↑ Michael Larabel (2011-10-05). "Samsung Introduces New Linux File-System: F2FS". phoronix.com. Retrieved 2012-12-07.
  4. ↑ "United States Patent: 5392427". Patft.uspto.gov. Retrieved 2012-06-15.
  5. ↑ "Linux Kernel Mailing List: logfs: remove from tree". Retrieved 2017-03-31.
  6. ↑ Pirkola, G. C. (June 1975). "A file system for a general-purpose time-sharing environment". Proceedings of the IEEE. 63 (6): 918–924. doi:10.1109/PROC.1975.9856. ISSN 0018-9219.
  7. ↑ IBM. 4690 OS Programming Guide Version 5.2, IBM document SC30-4137-01, 2007-12-06 ().
  8. ↑ Caldera (1997). Caldera OpenDOS Machine Readable Source Kit 7.01. The FDOS.EQU file in the machine readable source kit has equates for the corresponding directory entries.
  9. ↑ IBM (2003). Information about 4690 OS unique file distribution attributes, IBM document R1001487, 2003-07-30. ("Archived copy". Archived from the original on 2014-05-21. Retrieved 2014-05-20. ): "[...] file types are stored in the "Reserved bits" portion of the PC-DOS file directory structure [...] only 4690 respects and preserves these attributes. Various non-4690 operating systems take different actions if these bits are turned on [...] when copying from a diskette created on a 4690 system. [...] PC-DOS and Windows 2000 Professional will copy the file without error and zero the bits. OS/2 [...] 1.2 [...] will refuse to copy the file unless [...] first run CHKDSK /F on the file. After [...] CHKDSK, it will copy the file and zero the bits. [...] when [...] copy [...] back to the 4690 system, [...] file will copy as a local file."
  10. ↑ IBM. 4690 save and restore file distribution attributes. IBM document R1000622, 2010-08-31 ("Archived copy". Archived from the original on 2014-05-21. Retrieved 2014-05-20. ).
  11. ↑ http://moosefs.com/license.html
  12. ↑ "about.rst in trunk/docs – tahoe-lafs". Tahoe-lafs.org. Retrieved 2014-02-09.
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