mksquashfs (1)

NAME

mksquashfs - tool to create and append to squashfs filesystems

SYNOPSIS

mksquashfs SOURCE [SOURCE2 ...] DESTINATION [OPTIONS]

DESCRIPTION

Squashfs is a highly compressed read-only filesystem for Linux. It uses zlib compression to compress both files, inodes and directories. Inodes in the system are very small and all blocks are packed to minimize data overhead. Block sizes greater than 4K are supported up to a maximum of 64K.

Squashfs is intended for general read-only filesystem use, for archival use (i.e. in cases where a .tar.gz file may be used), and in constrained block device/memory systems (e.g. embedded systems) where low overhead is needed.

OPTIONS

Filesystem build options

-comp COMPRESSION

select COMPRESSION compression. Compressors available: gzip (default), lzo, xz.

-b BLOCK_SIZE

set data block to BLOCK_SIZE. Default 131072 bytes.

-no-exports

don't make the filesystem exportable via NFS.

-no-sparse

don't detect sparse files.

-no-xattrs

don't store extended attributes.

-xattrs

store extended attributes (default).

-noI

do not compress inode table.

-noD

do not compress data blocks.

-noF

do not compress fragment blocks.

-noX

do not compress extended attributes.

-no-fragments

do not use fragments.

-always-use-fragments

use fragment blocks for files larger than block size.

-no-duplicates

do not perform duplicate checking.

-all-root

make all files owned by root.

-force-uid uid

set all file uids to uid.

-force-gid gid

set all file gids to gid.

-nopad

do not pad filesystem to a multiple of 4K.

-keep-as-directory

if one source directory is specified, create a root directory containing that directory, rather than the contents of the directory.

Filesystem filter options

-p PSEUDO_DEFINITION

Add pseudo file definition.

-pf PSEUDO_FILE

Add list of pseudo file definitions.

-sort SORT_FILE

sort files according to priorities in SORT_FILE. One file or dir with priority per line. Priority -32768 to 32767, default priority 0.

-ef EXCLUDE_FILE

list of exclude dirs/files. One per line.

-wildcards

Allow extended shell wildcards (globbing) to be used in exclude dirs/files

-regex

Allow POSIX regular expressions to be used in exclude dirs/files.

Filesystem append options

-noappend

do not append to existing filesystem.

-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.

Mksquashfs runtime options:

-version

print version, licence and copyright message.

-recover NAME

recover filesystem data using recovery file NAME.

-no-recovery

don't generate a recovery file.

-info

print files written to filesystem.

-no-progress

don't display the progress bar.

-processors NUMBER

Use NUMBER processors. By default will use number of processors available.

-read-queue SIZE

Set input queue to SIZE Mbytes. Default 64 Mbytes.

-write-queue SIZE

Set output queue to SIZE Mbytes. Default 512 Mbytes.

-fragment-queue SIZE

Set fragment queue to SIZE Mbytes. Default 64 Mbytes.

Miscellaneous options

-root-owned

alternative name for -all-root.

-noInodeCompression

alternative name for -noI.

-noDataCompression

alternative name for -noD.

-noFragmentCompression

alternative name for -noF.

-noXattrCompression

alternative name for -noX.

Compressors available and compressor specific options

gzip (no options) (default)

lzo (no options)

xz

-Xbcj filter1,filter2,...,filterN

Compress using filter1,filter2,...,filterN in turn (in addition to no filter), and choose the best compression. Available filters: x86, arm, armthumb, powerpc, sparc, ia64.

-Xdict-size DICT_SIZE

Use DICT_SIZE as the XZ dictionary size. The dictionary size can be specified as a percentage of the block size, or as an absolute value. The dictionary size must be less than or equal to the block size and 8192 bytes or larger. It must also be storable in the xz header as either 2^n or as 2^n+2^(n+1). Example dict-sizes are 75%, 50%, 37.5%, 25%, or 32K, 16K, 8K etc.

SEE ALSO

unsquashfs(1)

HOMEPAGE

More information about mksquashfs and the squashfs filesystem can be found at <squashfs.sourceforge.net>.

AUTHOR

squashfs was written by Phillip Lougher <phillip@squashfs.org.uk>.

This manual page was written by Daniel Baumann <mail@daniel-baumann.ch>.