CHFS is a
file system
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 stored and retrieved. Without a file system, data placed in a storage medium would be one lar ...
developed at the Department of Software Engineering,
University of Szeged,
Hungary
Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croa ...
.
It was the first open source
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 u ...
-specific file system written for the
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 ...
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ef ...
. Intended usage is over raw flash devices on
embedded system
An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' ...
s like
ARM and
MIPS, the filesystem is less suitable for use on consumer
SSD
A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage. It is ...
(because consumer SSDs already make sure to not use the same physical blocks for writing modified data).
Structure
Similar to
UBIFS, the CHFS file system utilizes a separate layer for handling Flash aging and bad blocks, called EBH (erase block handler). The file system itself is modelled after
JFFS2, thus the internal structure is very similar.
ChewieFS
CHFS was originally called ChewieFS during development.
[ The name was changed to avoid legal issues and to have a more neutral name.]
See also
* 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 ...
* 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 ...
* chfs AIX command line option for modifying filesystems
References
External links
*
ChewieFS - a JFFS2 like flash filesystem for NetBSD
(Tamás Tóth, BSD-Day 2010)
*
Flash file systems
NetBSD
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