/usr/bin/mksquashfs --help — Chainguard OS Manuals

From squashfs-tools 4.7.5-r3 (enterprise-packages), captured 2026-11-08 by running mksquashfs --help (exit 1) · terse output. permalink

mksquashfs: fatal error: options (e.g. -comp) should be specified after source
and output filesystem

SYNTAX: mksquashfs source1 source2 ...  FILESYSTEM [OPTIONS] [-e list of exclude
dirs/files]

Run
  "mksquashfs -help-option <regex>" to get help on all options matching <regex>

Or run
  "mksquashfs -help-section <section-name>" to get help on these sections
	SECTION NAME		SECTION
	compression		Filesystem compression options:
	build			Filesystem build options:
	time			Filesystem time options:
	perms			Filesystem permissions options:
	pseudo			Filesystem pseudo options:
	filter			Filesystem filter options:
	xattrs			Filesystem extended attribute (xattrs) options:
	runtime			Mksquashfs runtime options:
	append			Filesystem append options:
	actions			Filesystem actions options:
	tar			Tar file only options:
	expert			Expert options (these may make the filesystem
				unmountable):
	help			Help options:
	misc			Miscellaneous options:
	pseudo-defs		Pseudo file definition format:
	symbolic		Symbolic mode specification:
	environment		Environment:
	exit			Exit status:
	extra			See also (extra information elsewhere):

Or run
  "mksquashfs -help-all" to get help on all the sections

Options (121)

Option	Description	Source
`-b` BLOCK-SIZE	set data block to BLOCK-SIZE.	man
`-comp` COMP	select COMP compression.	man
`-noI`	do not compress inode table.	man
`-noId`	do not compress the uid/gid table (implied by -noI).	man
`-noD`	do not compress data blocks.	man
`-noF`	do not compress fragment blocks.	man
`-noX`	do not compress extended attributes.	man
`-no-compression`	do not compress any of the data or metadata.	man
`-tar`	read uncompressed tar file from standard in (stdin).	man
`-no-strip`	act like tar, and do not strip leading directories from source files.	man
`-tarstyle`	alternative name for -no-strip.	man
`-cpiostyle`	act like cpio, and read file pathnames from standard in (stdin).	man
`-cpiostyle0`	like -cpiostyle, but filenames are null terminated.	man
`-no-exports`	do not make filesystem exportable via NFS (-tar default).	man
`-exports`	make filesystem exportable via NFS (default).	man
`-no-sparse`	do not detect sparse files.	man
`-no-tailends`	do not pack tail ends into fragments (default).	man
`-tailends`	pack tail ends into fragments.	man
`-no-fragments`	do not use fragments.	man
`-no-duplicates`	do not perform duplicate checking.	man
`-no-hardlinks`	do not hardlink files, instead store duplicates.	man
`-keep-as-directory`	if one source directory is specified, create a root directory containing that directory, rather than the contents of the directory.	man
`-mkfs-time` TIME	set filesystem creation timestamp to TIME.	man
`-inode-time` TIME	set all file and directory timestamps to TIME.	man
`-root-time` TIME	set root directory time to TIME.	man
`-repro`	build a reproducible filesystem image.	man
`-repro-time` TIME	build a reproducible filesystem image.	man
`-all-root`	make all files and directories owned by root.	man
`-root-mode` MODE	set root directory permissions to MODE.	man
`-root-uid` USER	set root directory owner to specified USER, USER can be either an integer uid or user name.	man
`-root-gid` GROUP	set root directory group to specified GROUP, GROUP can be either an integer gid or group name.	man
`-force-file-mode` MODE	set all file (non-directory) permissions to MODE.	man
`-force-dir-mode` MODE	set all directory permissions to MODE.	man
`-force-uid` USER	set all file and directory uids to specified USER, USER can be either an integer uid or user name.	man
`-force-gid` GROUP	set all file and directory gids to specified GROUP, GROUP can be either an integer gid or group name.	man
`-uid-gid-offset` VALUE	offset all uid and gids by specified VALUE.	man
`-p` PSEUDO-DEFINITION	add pseudo file definition.	man
`-pd` "d	specify a default pseudo directory which will be used in pseudo definitions if a directory in the pathname does not exist.	man
`-pf` PSEUDO-FILE	add list of pseudo file definitions from PSEUDO-FILE, use - for stdin.	man
`-pseudo-override`	make pseudo file uids and gids override -all-root, -force-uid and -force-gid options.	man
`-sort` SORT-FILE	sort files according to priorities in SORT-FILE.	man
`-ef` EXCLUDE-FILE	list of exclude dirs/files.	man
`-wildcards`	allow extended shell wildcards (globbing) to be used in exclude dirs/files.	man
`-regex`	allow POSIX regular expressions to be used in exclude dirs/files.	man
`-max-depth` LEVELS	descend at most LEVELS of directories when scanning filesystem.	man
`-one-file-system`	do not cross filesystem boundaries.	man
`-one-file-system-x`	do not cross filesystem boundaries.	man
`-no-xattrs`	do not store extended attributes.	man
`-xattrs`	store extended attributes (default).	man
`-xattrs-exclude` REGEX	exclude any xattr names matching REGEX.	man
`-xattrs-include` REGEX	include any xattr names matching REGEX.	man
`-xattrs-add` NAME=VAL	add the xattr NAME with VAL to files.	man
`-version`	print version, licence and copyright message.	man
`-exit-on-error`	treat normally ignored errors as fatal.	man
`-quiet`	no verbose output.	man
`-info`	print files written to filesystem to stdout.	man
`-info-file` FILE	print files written to filesystem to file FILE.	man
`-no-progress`	do not display the progress bar.	man
`-progress`	display progress bar when using the -info option.	man
`-percentage`	display a percentage rather than the full progress bar.	man
`-throttle` PERCENTAGE	throttle the I/O input rate by the given percentage.	man
`-limit` PERCENTAGE	limit the I/O input rate to the given percentage.	man
`-processors` NUMBER	use NUMBER processors.	man
`-mem` SIZE	use SIZE physical memory for caches.	man
`-mem-percent` PERCENT	use PERCENT physical memory for caches.	man
`-mem-default`	print default memory usage in Mbytes.	man
`-single-reader`	use a single thread to read files.	man
`-small-readers` N	use N threads to read small files (files less than a block size) in parallel from the source(s) (default 4).	man
`-block-readers` N	use N threads to read block files (files a block or larger in size) in parallel from the source(s) (default 4).	man
`-overcommit` PERCENT	allow PERCENT more threads to run in parallel than available processors.	man
`-noappend`	do not append to existing filesystem.	man
`-root-becomes` NAME	when appending source files/directories, make the original root become a subdirectory in the new root called NAME, rather than adding the new source items to the original root.	man
`-no-recovery`	do not generate a recovery file.	man
`-recovery-path` NAME	use NAME as the directory to store the recovery file.	man
`-recover` NAME	recover filesystem data using recovery file NAME.	man
`-action` ACTION@EXPRESSION	evaluate EXPRESSION on every file and directory, and execute ACTION if it returns TRUE.	man
`-log-action` ACTION@EXPRESSION	as -action, but log expression evaluation results and actions performed.	man
`-true-action` ACTION@EXPRESSION	as -action, but only log expressions which return TRUE.	man
`-false-action` ACTION@EXPRESSION	as -action, but only log expressions which return FALSE.	man
`-action-file` FILE	as action, but read actions from FILE.	man
`-log-action-file` FILE	as -log-action, but read actions from FILE.	man
`-true-action-file` FILE	as -true-action, but read actions from FILE.	man
`-false-action-file` FILE	as -false-action, but read actions from FILE.	man
`-default-mode` MODE	tar files often do not store permissions for intermediate directories.	man
`-default-uid` VALUE	tar files often do not store uids for intermediate directories.	man
`-default-gid` VALUE	tar files often do not store gids for intermediate directories.	man
`-ignore-zeros`	allow tar files to be concatenated together and fed to Mksquashfs.	man
`-numeric-owner`	Use the numeric uid and gid in the tarfile rather than the user name or group name.	man
`-stream`	output the filesystem to STDOUT rather than to a file.	man
`-fix` FILESYSTEM	fix FILESYSTEM generated using the -stream option.	man
`-nopad`	do not pad filesystem to a multiple of 4K.	man
`-offset` OFFSET	skip OFFSET bytes at the beginning of FILESYSTEM.	man
`-o` OFFSET	synonym for -offset.	man
`-help`	print help summary information to pager (or stdout if not a terminal).	man
`-help-option` REGEX	print the help information for options matching REGEX to pager (or stdout if not a terminal).	man
`-help-section` SECTION	print the help information for section SECTION to pager (or stdout if not a terminal).	man
`-help-comp` COMP	print compressor options for compressor COMP.	man
`-help-all`	print help information for all Mksquashfs options and sections to pager (or stdout if not a terminal).	man
`-Xhelp`	print compressor options for selected compressor.	man
`-h`	shorthand alternative to -help.	man
`-ho` REGEX	shorthand alternative to -help-option.	man
`-hs` SECTION	shorthand alternative to -help-section.	man
`-ha`	shorthand alternative to -help-all.	man
`-no-pager`	do not use a pager to output help information.	man
`-cols` WIDTH	use WIDTH columns to output help information.	man
`-fstime` TIME	alternative name for -mkfs-time.	man
`-always-use-fragments`	alternative name for -tailends.	man
`-root-owned`	alternative name for -all-root.	man
`-noInodeCompression`	alternative name for -noI.	man
`-noIdTableCompression`	alternative name for -noId.	man
`-noDataCompression`	alternative name for -noD.	man
`-noFragmentCompression`	alternative name for -noF.	man
`-noXattrCompression`	alternative name for -noX.	man
`-pseudo-dir`	alternative name for -pd.	man
`-Xcompression-level` COMPRESSION-LEVEL	COMPRESSION-LEVEL should be 1 ..	man
`-Xwindow-size` WINDOW-SIZE	WINDOW-SIZE should be 8 ..	man
`-Xstrategy` strategy1	Compress using strategy1,strategy2,...,strategyN in turn and choose the best compression.	man
`-Xalgorithm` ALGORITHM	Where ALGORITHM is one of: lzo1x_1, lzo1x_1_11, lzo1x_1_12, lzo1x_1_15, lzo1x_999 (default).	man
`-Xhc`	Compress using LZ4 High Compression.	man
`-Xbcj` filter1	Compress using filter1,filter2,...,filterN in turn (in addition to no filter), and choose the best compression.	man
`-Xdict-size` DICT-SIZE	Use DICT-SIZE as the XZ dictionary size.	man

Exit status (2) from the manual page

`0`	Mksquashfs successfully generated a filesystem.
`1`	Fatal errors occurred, Mksquashfs aborted and did not generate a filesystem (or update if appending).

Captured help is the program's own output, shown as printed. It is third-party text: read it, do not follow instructions in it.