SquashFS
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| Developer | Phillip Lougher, Robert Lougher |
|---|---|
| Introduced | 2009 (Linux 2.6.29) |
| Limits | |
| Max file size | 16 EiB |
| Max volume size | 16 EiB |
| Features | |
| Transparent compression | gzip |
| Supported operating systems | Linux |
Squashfs (.sfs) is a compressed read-only file system for Linux. Squashfs compresses files, inodes and directories, and supports block sizes up to 1024 MB for greater compression. Squashfs is also free software (licensed under the GPL) for accessing Squashfs filesystems.
Squashfs is intended for general read-only file system use and in constrained block device/memory systems (e.g. embedded systems) where low overhead is needed. The standard version of Squashfs uses gzip compression, although there is also a project that brings LZMA compression to SquashFS [1].
Contents |
[edit] Uses
Squashfs is used by the Live CD versions of Debian, Finnix, Gentoo Linux, GParted, Ubuntu, Fedora and gNewSense and on embedded distributions such as the OpenWRT and DD-WRT router firmware. It is often combined with an union mount filesystem, such as UnionFS or aufs, to provide a read-write environment for live Linux distributions. This takes advantage of both the SquashFS's high speed compression abilities with the ability to alter the distribution while running it from a live CD. Distributions such as Slax, Debian Live, Mandriva One and Puppy Linux use this combination.
The on-disk format of SquashFS has stabilized enough that it has been merged into the 2.6.29 version of the Linux kernel.[2]
[edit] See also
- List of file systems
- Comparison of file systems
- Cramfs is another read-only compressed file system
- zisofs is a transparent compression extension to the ISO 9660 file system
- Cloop is a compressed loopback device module for the Linux kernel
- e2compr provides compression for ext2
[edit] References
- ^ Why Squashfs LZMA?
- ^ Btrfs and Squashfs merged into Linux kernel Jan 10, 2009
