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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; ran-
       dom  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)