mkfs.cramfs - make compressed ROM file system
mkfs.cramfs [options] directory file
Files on cramfs file systems are zlib-compressed one page at a time to allow random read access. The metadata is not compressed, but is expressed in a terse representation that is more space-efficient than conventional file systems.
The file system is intentionally read-only to simplify its design; random write access for compressed files is difficult to implement. cramfs ships with a utility (mkcramfs(8)) to pack files into new cramfs images.
File sizes are limited to less than 16 MB.
Maximum file system size is a little under 272 MB. (The last file on the file system must begin before the 256 MB block, but can extend past it.)
The directory is simply the root of the directory tree that we want to generate a compressed filesystem out of.
The file will contain the cram file system, which later can be mounted.
-N big, little, host
For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.
The mkfs.cramfs command is part of the util-linux package which can be downloaded from Linux Kernel Archive https://www.kernel.org/pub/linux/utils/util-linux/.