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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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NAME | SYNOPSIS | DESCRIPTION | ARGUMENTS | OPTIONS | EXIT STATUS | SEE ALSO | REPORTING BUGS | AVAILABILITY |
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MKFS.CRAMFS(8) System Administration MKFS.CRAMFS(8)
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.
-v
Enable verbose messaging.
-E
Treat all warnings as errors, which are reflected as command
exit status.
-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.
-l[=mode]
Use exclusive BSD lock for device or file it operates. The
optional argument mode can be yes, no (or 1 and 0) or
nonblock. If the mode argument is omitted, it defaults to
"yes". This option overwrites environment variable
$LOCK_BLOCK_DEVICE. The default is not to use any lock at
all, but it’s recommended to avoid collisions with udevd or
other tools.
-h, --help
Display help text and exit.
-V, --version
Print version and exit.
0
success
8
operation error, such as unable to allocate memory
fsck.cramfs(8), mount(8)
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/>. This page
is part of the util-linux (a random collection of Linux
utilities) project. Information about the project can be found at
⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
a bug report for this manual page, send it to
util-linux@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-10.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page),
send a mail to man-pages@man7.org
util-linux 2.39.594-1e0ad 2023-07-19 MKFS.CRAMFS(8)
Pages that refer to this page: fsck.cramfs(8), systemd-makefs@.service(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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