Squashfs 3.1 review

Squashfs project is a compressed read-only filesystem for Linux

License: GPL (GNU General Public License) File size: 0K Developer: Phil Lougher

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Squashfs project is a compressed read-only filesystem for Linux. Squashfs is intended for general read-only filesystem use, for archival use (i.e. in cases where a .tar.gz file may be used), and in constrained block device/memory systems (e.g. embedded systems) where low overhead is needed.

The filesystem is currently stable, and has been tested on PowerPC, i586, Sparc and ARM architectures.

Here are some key features of "Squashfs":
Data, inodes and directories are compressed.
Squashfs stores full uid/gids (32 bits), and file creation time.
Files up to 2^32 bytes are supported. Filesystems can be up to 2^32 bytes.
Inode and directory data are highly compacted, and packed on byte boundaries. Each compressed inode is on average 8 bytes in length (the exact length varies on file type, i.e. regular file, directory, symbolic link, and block/char device inodes have different sizes).
Squashfs can use block sizes up to 64K (the default size is 64K). Using 64K blocks achieves greater compression ratios than the normal 4K block size.
File duplicates are detected and removed.
Both big and little endian architectures are supported. The mksquashfs program can generate filesystems for different endian architectures for cases where the host byte ordering is different to the target. This is useful for embedded systems.

What's New in This Release:
This version applies some major improvements to the Squashfs-tools (Mksquashfs and Unsquashfs).
In particular, Mksquashfs has been parallelized.
There are also some major bugfixes, numerous smaller improvements and bugfixes, and patches for new Linux kernels.