Squashfs

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(Changed data compression to optional, and provide reference. Provide examples and references of where else SquashFS sees its deployment.)
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* Embedded devices like network routers<ref>[https://openwrt.org/docs/techref/flash.layout The OpenWrt Flash Layout - Technical Reference - openwrt.org]</ref><ref>[https://github.com/ReFirmLabs/binwalk/issues/301 problems extracting squashfs-image #301 - binwalk - GitHub]</ref><ref>[https://embeddedbits.org/reverse-engineering-my-routers-firmware-with-binwalk-embeddedbits/ Reverse engineering my router's firmware with binwalk - embeddedbits.org]</ref>, or in Android powered devices.<ref>[https://android.stackexchange.com/questions/258236/squashfs-explanation-for-android-system SquashFS explanation for Android system - Android Enthusiasts - Stack Exchange]</ref>
 
* Embedded devices like network routers<ref>[https://openwrt.org/docs/techref/flash.layout The OpenWrt Flash Layout - Technical Reference - openwrt.org]</ref><ref>[https://github.com/ReFirmLabs/binwalk/issues/301 problems extracting squashfs-image #301 - binwalk - GitHub]</ref><ref>[https://embeddedbits.org/reverse-engineering-my-routers-firmware-with-binwalk-embeddedbits/ Reverse engineering my router's firmware with binwalk - embeddedbits.org]</ref>, or in Android powered devices.<ref>[https://android.stackexchange.com/questions/258236/squashfs-explanation-for-android-system SquashFS explanation for Android system - Android Enthusiasts - Stack Exchange]</ref>
 
* Modern AppImage,<ref>[[wikipedia:AppImage#History|History of AppImage - Wikipedia]]</ref>, or [[Snap]]<ref>[[wikipedia:Snap_(software)#Support|Snap - support section - Wikipedia]]</ref> as a way portable software distribution on Linux.
 
* Modern AppImage,<ref>[[wikipedia:AppImage#History|History of AppImage - Wikipedia]]</ref>, or [[Snap]]<ref>[[wikipedia:Snap_(software)#Support|Snap - support section - Wikipedia]]</ref> as a way portable software distribution on Linux.
* Storage of other data, such as disk images.<ref>[https://www.foo.be/2017/01/Squashfs_As_A_Forensic_Container Squashfs As a Forensic Container - foo.be]</ref> Under Windows, Squashfs contents can be opened/extracted via [[7-Zip]].<ref>[https://stackoverflow.com/a/36877207 python2.7 How to handle squashfs in Windows - StackOverflow]</ref>
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* Storage of other data, such as disk images.<ref>[https://www.foo.be/2017/01/Squashfs_As_A_Forensic_Container Squashfs As a Forensic Container - foo.be]</ref>
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Under [[Microsoft Windows|Windows]], SquashFS contents can be opened/extracted via [[7-Zip]].<ref>[https://stackoverflow.com/a/36877207 python2.7 How to handle squashfs in Windows - StackOverflow]</ref>
  
 
See also [[cramfs]].
 
See also [[cramfs]].

Latest revision as of 06:55, 20 August 2025

File Format
Name Squashfs
Ontology
Extension(s) .sfs[1]
Wikidata ID Q389314
Compression lossless, optional
Magic Bytes 68 73 71 73 (little-endian)
73 71 73 68 (big-endian)
Developed By Phillip Lougher[2]
Maintained By Phillip Lougher
Released 2002

Squashfs is read-only filesystem that features optional compression[3] for Linux. Typically used as a "live image" for booting Linux off a removable storage (e.g. USB, CD/DVD), minus components like the bootloader, kernel and initramfs.[4] It is also used in:

  • Embedded devices like network routers[5][6][7], or in Android powered devices.[8]
  • Modern AppImage,[9], or Snap[10] as a way portable software distribution on Linux.
  • Storage of other data, such as disk images.[11]

Under Windows, SquashFS contents can be opened/extracted via 7-Zip.[12]

See also cramfs.

Contents

[edit] Identification

SquashFS files created on little-endian machines begins with hexadecimal 68 73 71 73, which translates to "hsqs" in ASCII. SquashFS files created on big-endian machines with hexadecimal 73 71 73 68, which translates to "sqsh" in ASCII.

[edit] Examples

Create a Squashfs (file system) image from current/present directory and output it into its parent directory:

 $ mksquashfs . ../example.squashfs -b 1048576 -comp xz -Xdict-size 100%

Open a Squashfs image (as root) from present directory and have its contents visible in /mnt:

 # mount example.squashfs /mnt

Open a Squashfs image (as user) from present directory and have its contents visible in /mnt/temp:

 $ squashfuse example.squashfs /mnt/temp

[edit] Software

[edit] Sample files

[edit] Links

[edit] References

  1. What are the commonly accepted file name extension for squashfs? #259 - GitHub
  2. (Squashfs-announce) Squashfs1.2 released - 2003-03-13 05:30:45 - SourceForge mailman
  3. [feature request]: mksquashfs: Add --no-compression flag to disable all compression #206 - squashfs-tools - GitHub
  4. EROFS For Live Media - Fedora Project
  5. The OpenWrt Flash Layout - Technical Reference - openwrt.org
  6. problems extracting squashfs-image #301 - binwalk - GitHub
  7. Reverse engineering my router's firmware with binwalk - embeddedbits.org
  8. SquashFS explanation for Android system - Android Enthusiasts - Stack Exchange
  9. History of AppImage - Wikipedia
  10. Snap - support section - Wikipedia
  11. Squashfs As a Forensic Container - foo.be
  12. python2.7 How to handle squashfs in Windows - StackOverflow
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