Developer(s)University of Szeged
Full nameChip File System
Introduced2011 with NetBSD 6.0
Directory contentsRed–black trees
File system permissionsPOSIX
Supported operating systemsNetBSD

CHFS is a file system developed at the Department of Software Engineering, University of Szeged, Hungary.[1] It was the first open source flash memory-specific file system written for the NetBSD operating system. Intended usage is over raw flash devices on embedded systems like ARM and MIPS, the filesystem is less suitable for use on consumer SSD[2] (because consumer SSDs already make sure to 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 and bad blocks, called EBH (erase block handler). The file system itself is modelled after JFFS2, thus the internal structure is very similar.


CHFS was originally called ChewieFS during development.[1] The name was changed to avoid legal issues and to have a more neutral name.[3]

See also


  1. ^ a b Tamás Tóth (2011-11-10). "ChewieFS". tech-kern@NetBSD (Mailing list). Retrieved February 4, 2012.
  2. ^ Ádám Hóka (2011-11-10). "Re: ChewieFS". tech-kern@NetBSD (Mailing list). Retrieved 2019-03-05.
  3. ^ Ádám Hóka (2011-11-24). "Import mount_chfs for CHFS". Retrieved 2021-05-23.