This is an incomplete list of

log-structured file system A log-structured filesystem is a file system in which data and metadata are written sequentially to a circular buffer, called a log. The design was first proposed in 1988 by John K. Ousterhout and Fred Douglis and first implemented in 1992 by Ou ...

implementations. * James T, Brady while in IBM Poughkeepsie Lab conceived a log structured paging file system in 1979 which was implemented in

MVS Multiple Virtual Storage, more commonly called MVS, was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers. IBM developed MVS, along with OS/VS1 and SVS, as a successor to OS/360. It is unrelated ...

SP2 in 1980."1981 IBM Corporate Technical Recognition Event Book, Outstanding Innovation Award, “Virtual Storage Disk Paging”" * John K. Ousterhout and

Mendel Rosenblum Mendel Rosenblum (born 1962) is a professor of Computer Science at Stanford University and co-founder of VMware. Early life Mendel Rosenblum was born in 1962. He attended the University of Virginia, where he received a degree in mathematics. Whil ...

implemented the first log-structured file system for the

Sprite operating system Sprite is an experimental Unix-like distributed operating system developed at the University of California, Berkeley by John Ousterhout's research group between 1984 and 1992. Its notable features include support for single system image on compu ...

in 1992.Rosenblum, Mendel and Ousterhout, John K. (June 1990) -
The LFS Storage Manager
. ''Proceedings of the 1990 Summer Usenix''. pp315-324.Rosenblum, Mendel and Ousterhout, John K. (February 1992) -

. ''ACM Transactions on Computer Systems, Vol. 10 Issue 1''. pp26-52. * BSD-LFS, an implementation by

Margo Seltzer Margo Ilene Seltzer is a professor and researcher in computer systems. She is currently the Canada 150 Research Chair in Computer Systems and the Cheriton Family Chair in Computer Science at the University of British Columbia. Previously, Seltzer ...

was added to 4.4BSD, and was later ported to

386BSD 386BSD (also known as "Jolix") is a discontinued Unix operating system based on the Berkeley Software Distribution (BSD). It was released in 1992 and ran on PC-compatible computer systems based on the 32-bit Intel 80386 microprocessor. 386BSD inn ...

. It lacked support for snapshots. It was removed from FreeBSD and OpenBSD, but still lives on in

NetBSD NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is a ...

. * Plan 9's

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

file system is also log-structured and supports snapshots. *

NILFS NILFS or NILFS2 (''New Implementation of a Log-structured File System'') is a log-structured file system implementation for the Linux kernel. It was developed by Nippon Telegraph and Telephone Corporation (NTT) CyberSpace Laboratories and a comm ...

is a log-structured file system implementation for

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

NTT/Verio Verio is a global web hosting provider headquartered in the United States. Incorporated in 1996 in Denver, Colorado, it is a wholly owned subsidiary of Nippon Telegraph and Telephone (NTT) Communications, which acquired the company in 2000. Ve ...

which supports snapshots. * LinLogFS (formerly dtfs) and LFS are log-structured file system implementations for Linux. The latter was part of Google Summer of Code 2005. Both projects have been abandoned. * LFS is another log-structured file system for Linux developed by Charles University, Prague. It was to include support for snapshots and indexed directories, but development has since ceased. *

Write Anywhere File Layout The Write Anywhere File Layout (WAFL) is a proprietary file system that supports large, high-performance RAID arrays, quick restarts without lengthy consistency checks in the event of a crash or power failure, and growing the filesystems size q ...

(WAFL) by

NetApp NetApp, Inc. is an American hybrid cloud data services and data management company headquartered in San Jose, California. It has ranked in the Fortune 500 from 2012–2021. Founded in 1992 with an IPO in 1995, NetApp offers cloud data services ...

is a file layout that supports large, high-performance RAID arrays, quick restarts without lengthy consistency checks in the event of a crash or power failure, and growing the filesystems size quickly. Built using log-structured file system concept, snapshots and off-line

data deduplication In computing, data deduplication is a technique for eliminating duplicate copies of repeating data. Successful implementation of the technique can improve storage utilization, which may in turn lower capital expenditure by reducing the overall amou ...

. * LSFS is a log-structured file system with writable snapshots and inline

created by

StarWind Software StarWind Software, Inc. is a privately held Beverly, Massachusetts-based computer software and hardware appliance company specializing in storage virtualization and software-defined storage. History StarWind Software began in 2008 as a spin ...

. * Cache Accelerated Sequential Layout (CASL) is a proprietary log-structured filesystem developed by

Nimble Storage Nimble Storage, founded in 2008, produced hardware and software products for data storage, specifically data storage arrays that use the iSCSI and Fibre Channel protocols and includes data backup and data protection features. Nimble is now a sub ...

that uses Solid State Devices to cache traditional hard drives. *

ObjectiveFS ObjectiveFS is a distributed file system developed by Objective Security Corp. It is a POSIX-compliant file system built with an object store backend.Christophe Bard"LeMagIT: ObjectiveFS: a POSIX file system on top of S3 (original article in Frenc ...

is a log-structured FUSE filesystem that uses cloud object stores (e.g. Amazon S3, Google Cloud Storage and private cloud object store). *

NOVA A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramati ...

for byte-addressable

persistent memory In computer science, persistent memory is any method or apparatus for efficiently storing data structures such that they can continue to be accessed using memory instructions or memory APIs even after the end of the process that created or last mo ...

(for example non-volatile dual in-line memory module (NVDIMM) and

3D XPoint 3D XPoint (pronounced ''three-D cross point'') is a discontinued non-volatile memory (NVM) technology developed jointly by Intel and Micron Technology. It was announced in July 2015 and is available on the open market under the brand name Optane ...

) for Linux developed at the University of California, San Diego, US. * Spiralog was a log-structured filesystem created by

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president unt ...

for the

OpenVMS OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using Ope ...

operating system. Spiralog was an optional product, and was discontinued due to a variety of problems, including issues with handling full volumes. Some kinds of storage media, such as

flash memory Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR and NAND logic gates. Both us ...

and

CD-RW CD-RW (Compact Disc-Rewritable) is a digital media, digital optical disc data storage device, storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written. CD-RWs, as opposed to CDs, require ...

, slowly degrade as they are written to and have a limited number of erase/write cycles at any one location. Log-structured file systems are sometimes used on these media because they make fewer in-place writes and thus prolong the life of the device by

wear leveling Wear leveling (also written as wear levelling) is a technique Wear leveling techniques for flash memory systems. for prolonging the service life of some kinds of erasable computer storage media, such as flash memory, which is used in solid-state d ...

. The more common such file systems include: * UDF is a file system commonly used on

optical disc In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. ...

s. *

JFFS The Journaling Flash File System (or JFFS) is a log-structured file system for use on NOR flash memory devices on the Linux operating system. It has been superseded by JFFS2. Design Flash memory (specifically NOR flash) must be erased prio ...

and its successor

JFFS2 Journalling Flash File System version 2 or JFFS2 is a log-structured file system for use with flash memory devices. It is the successor to JFFS. JFFS2 has been included into the Linux kernel since September 23, 2001, when it was merged into the ...

are simple

file systems intended for raw flash-based devices. *

UBIFS UBIFS (UBI File System, more fully Unsorted Block Image File System) is a flash file system for unmanaged flash memory devices. UBIFS works on top of an UBI (unsorted block image) layer, which is itself on top of a memory technology device (MT ...

is a filesystem for raw NAND flash media and also intended to replace

. *

LogFS LogFS is a Linux log-structured and scalable flash file system, intended for use on large devices of flash memory. It is written by Jörn Engel and in part sponsored by the CE Linux Forum. LogFS was introduced in the mainline Linux kernel in v ...

is a scalable flash filesystem for

that works on both raw flash media and block devices, intended to replace

. *

YAFFS Yaffs (Yet Another Flash File System) is a file system designed and written by Charles Manning for the company Aleph One. Yaffs1 was the first version of this file system and was designed for the then-current NAND chips with 512 byte page size ( ...

is a raw NAND flash-specific file system for many operating systems (including Linux). *

F2FS F2FS (Flash-Friendly File System) is a flash file system initially developed by Samsung Electronics for the Linux kernel. The motive for F2FS was to build a file system that, from the start, takes into account the characteristics of NAND flash ...

is a new file system designed for the NAND flash memory-based storage devices on Linux.

References

{{DEFAULTSORT:Log-structured file systems Lists of software Computing-related lists Computer file systems

See also

References