F2FS (Flash-Friendly File System) is a flash file system initially developed by Samsung Electronics for the Linux kernel. It’s a good choice when installing Linux to an eMMC, SSD, NVMe, SDCard, or a flash-based USB device.
F2FS was designed on a basis of a log-structured file system approach, which it adapted to newer forms of storage. It aims to remedy some known issues of the older log-structured file systems, such as the snowball effect of wandering trees and high cleaning overhead.
In addition, since a NAND-based storage device shows different characteristics according to its internal geometry or flash memory management scheme (such as the Flash Translation Layer or FTL), it supports various parameters not only for configuring on-disk layout, but also for selecting allocation and cleaning algorithms.
- Multi-head logging.
- Multi-level hash table for directory entries.
- Static/Dynamic hot and cold data separation.
- Adaptive logging scheme.
- Configurable operational units.
- Dual checkpoint.
- Roll-back and roll-forward recovery.
- Heap-style block allocation
- TRIM/FITRIM support.
- Online fs defragmentation/file defragmentation.
- Inline xattrs.
- Inline data.
- Inline dir.
- Offline filesystem check (Check and fix inconsistency).
- Atomic operations – very limited functionality for atomic write support.
- Filesystem-level encryption.
- Offline resizing – expand existing partition with resize.f2fs.
- Inner periodically data flush – try to flush user data before starting a checkpoint. So user’s data written after last checkpoint which may not be fsynced could be saved
- Extent cache – rb-tree based extent cache.
- Move_file_range – moving a range of data blocks from source file to destination file.
- Host-managed SMR.
- Multiple devices support – shows them entirely as one big volume under one f2fs instance.
- Large IO submission – IO alignment by filling dummy blocks in DATA and NODE write bio.
- Disk Quota (user/group).
- Cleaning both on demand and in the background. On-demand cleaning is triggered when there are not enough free segments to serve VFS calls. Background cleaner is operated by a kernel thread, and triggers the cleaning job when the system is idle.
- Cleaning Overhead:
- Support a background cleaning process.
- Support greedy and cost-benefit algorithms for victim selection policies.
- Support multi-head logs for static/dynamic hot and cold data separation.
- Introduce adaptive logging for efficient block allocation.
Developer: Samsung Electronics, Motorola Mobility, Huawei and Google
License: GNU General Public License version 2 only
|New to Linux? Read our Linux for Starters series. We start right at the basics and teach you everything you need to know to get started with Linux.|
|The largest compilation of the best free and open source software in the universe. Each article is supplied with a legendary ratings chart helping you to make informed decisions.|
|Hundreds of in-depth reviews offering our unbiased and expert opinion on software. We offer helpful and impartial information.|
|Replace proprietary software with open source alternatives: Google, Microsoft, Apple, Adobe, IBM, Autodesk, Oracle, Atlassian, Corel, Cisco, Intuit, and SAS.|
|Getting Started with Docker helps you master Docker, a set of platform as a service products that delivers software in packages called containers.|
|Essential Linux system tools focuses on small, indispensable utilities, useful for system administrators as well as regular users.|
|Linux utilities to maximise your productivity. Small, indispensable tools, useful for anyone running a Linux machine.|
|Home computers became commonplace in the 1980s. Emulate home computers including the Commodore 64, Amiga, Atari ST, ZX81, Amstrad CPC, and ZX Spectrum.|
|Now and Then examines how promising open source software fared over the years. It can be a bumpy ride.|
|Linux at Home looks at a range of home activities where Linux can play its part, making the most of our time at home, keeping active and engaged.|
|Linux Candy reveals the lighter side of Linux. Have some fun and escape from the daily drudgery.|
|Best Free Android Apps. We showcase free Android apps that are definitely worth downloading. There's a strict eligibility criteria for inclusion in this series.|
|These best free books accelerate your learning of every programming language. Learn a new language today!|
|These free tutorials offer the perfect tonic to our free programming books series.|
|Stars and Stripes is an occasional series looking at the impact of Linux in the USA.|