MKFS.CRAMFS(8)                   System Administration                   MKFS.CRAMFS(8)

NAME
       mkfs.cramfs - make compressed ROM file system

SYNOPSIS
       mkfs.cramfs [options] directory file

DESCRIPTION
       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) 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.)

ARGUMENTS
       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.

OPTIONS
       -v     Enable verbose messaging.

       -E     Treat  all  warnings  as  errors,  which  are reflected as command return
              value.

       -b blocksize
              Use defined block size, which has to be divisible by page size.

       -e edition
              Use defined file system edition number in superblock.

       -N big, little, host
              Use defined endianness.  Value defaults to host.

       -i file
              Insert a file to cramfs file system.

       -n name
              Set name of the cramfs file system.

       -p     Pad by 512 bytes for boot code.

       -s     This option is ignored.  Originally the  -s  turned  on  directory  entry
              sorting.

       -z     Make explicit holes.

       -h, --help
              Display help text and exit.

       -V, --version
              Display version information and exit.

EXIT STATUS
              0      success
              8      operation error, such as unable to allocate memory

SEE ALSO
       fsck.cramfs(8), mount(8)

AVAILABILITY
       The  example  command  is  part  of the util-linux package and is available from
       Linux Kernel Archive ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩.

util-linux                             April 2013                        MKFS.CRAMFS(8)

usage: mkfs.cramfs [-h] [-v] [-b blksize] [-e edition] [-N endian] [-i file] [-n name] dirname outfile
 -v         be verbose
 -E         make all warnings errors (non-zero exit status)
 -b blksize use this blocksize, must equal page size
 -e edition set edition number (part of fsid)
 -N endian  set cramfs endianness (big|little|host), default host
 -i file    insert a file image into the filesystem
 -n name    set name of cramfs filesystem
 -p         pad by 512 bytes for boot code
 -s         sort directory entries (old option, ignored)
 -z         make explicit holes
 dirname    root of the filesystem to be compressed
 outfile    output file

 -h, --help     display this help
 -V, --version  display version

For more details see mkfs.cramfs(8).