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 1 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, Gentoo Linux, Ubuntu, Fedora and on embedded distributions such as the OpenWRT and DD-WRT router firmware. It is often combined with a 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
