2008; 16 years ago (2008) with Linux kernel 2.6.27
Structures
Directory contents
B+ trees
Limits
Allowed filename characters
Any byte except NUL and forward slash "/"[citation needed]
Features
Forks
Yes
Attributes
Yes
File system permissions
Unix permissions
Transparent compression
Yes
Other
Supported operating systems
Linux
UBIFS (UBI File System, more fully Unsorted Block Image File System) is a flash file system for unmanaged flash memory devices.[1]
UBIFS works on top of an UBI (unsorted block image) layer,[2] which is itself on top of a memory technology device (MTD) layer.[3]
The file system is developed by Nokia engineers with help of the University of Szeged, Hungary. Development began in earnest in 2007, with the first stable release made to Linux kernel 2.6.27 in October 2008.
[4]
Two major differences between UBIFS and JFFS2 are that UBIFS supports write caching,[5] and UBIFS errs on the pessimistic side of free space calculation.[6]
UBIFS tends to perform better than JFFS2 for large NAND flash memory devices.[7] This is a consequence of the UBIFS design goals:[8] faster mounting, quicker access to large files, and improved write speeds. UBIFS also preserves or improves upon JFFS2's on-the-fly compression, recoverability and power fail tolerance.[8] UBIFS's on-the-fly data compression allows zlib (deflate algorithm), LZO or Zstandard.
UBIFS stores indexes in flash whereas JFFS2 stores filesystem indexes in memory.[9] This directly impacts the scalability of JFFS2 as the tables must be rebuilt every time the volume is mounted. Also, the JFFS2 tables may consume enough system RAM that some images may be unusable.
^Jonathan Corbet (2 April 2008). "UBIFS". LWN.net. Retrieved 18 December 2016.
^"UBIFS – UBI File-System: Big red note". 22 January 2015. Retrieved 18 December 2016. It does not work on top of block devices. UBIFS was designed to work on top of raw flash.
^"UBIFS – UBI File-System: Overview". 22 January 2015. Retrieved 18 December 2016.
^Artem Bityutskiy (27 March 2008). "UBIFS – new flash file system". Retrieved 18 December 2016.
^"UBIFS – UBI File-System: Write-back support". 22 January 2015. Retrieved 18 December 2016.
^"UBIFS FAQ and HOWTO: Why does df report too little free space?". 18 December 2015. Retrieved 18 December 2016.
^"UBIFS – UBI File-System: Scalability". 22 January 2015. Retrieved 18 December 2016.
^ abBityutskiy, Artem; Hunter, Adrian (24 September 2008). "UBIFS File System" (PDF). p. 9.
^Adrian Hunter (27 March 2008). "A Brief Introduction to the Design of UBIFS" (PDF).
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...
NAND flash too. UBIFSUBIFS has been merged since Linux 2.6.22 in 2008. UBIFS has been actively developed from its initial merge. UBIFS has documentation...
least three file systems have been developed as JFFS2 replacements: LogFS, UBIFS, and YAFFS. JFFS2 introduced: Support for NAND flash devices. This involved...
kernel. When using an MTD, the use of an MTD aware file system such as UBIFS, JFFS2 or YAFFS is recommended. The MTD subsystem exports block devices...
using various file systems, including cramfs, JFFS2, romfs, SquashFS and UBIFS.: 6–7, 18 Buildroot is free and open-source software, maintained by Peter...
flash translation layer (FTL) or Memory Technology Device (MTD), there are UBIFS, JFFS2 and YAFFS, among others. SquashFS is a common compressed read-only...
in June 2015 F2FS, added in Linux kernel 4.2[non-primary source needed] UBIFS, added in Linux kernel 4.10 CephFS, added in Linux kernel 6.6 APFS, macOS...
implementing error correction, bad block re-mapping and wear-leveling. UBIFS – successor of JFFS2, optimized to utilize NAND and NOR flash. Write Anywhere...
/home/user/MyDocs with about 27 GB of free space. The 256 MB NAND is formatted as UBIFS and contains the bootloader, kernel image and root directory "/" with about...
not use the same physical blocks for writing modified data). Similar to UBIFS, the CHFS file system utilizes a separate layer for handling Flash aging...
needed] Free and open-source software portal List of file systems JFFS JFFS2 UBIFS LogFS NILFS, a New Implementation of a Log-structured File System Open NAND...
skips obsolete ones, thus reclaiming space. List of file systems NILFS UBIFS YAFFS Woodhouse, David (2003-07-09). "JFFS2: The Journalling Flash File...
the algorithm requires reserving only a handful of flash-memory blocks. UBIFS Inode pointer structure Jörn Engel; Robert Mertens (2005-09-18). "LogFS...
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