1MKSQUASHFS(1) create and append squashfs filesystems MKSQUASHFS(1)
2
6 mksquashfs - tool to create and append to squashfs filesystems
7
10 mksquashfs SOURCE [SOURCE2 ...] DESTINATION [OPTIONS]
11
14 Squashfs is a highly compressed read-only filesystem for Linux. It uses
15 zlib compression to compress both files, inodes and directories. Inodes
16 in the system are very small and all blocks are packed to minimize data
17 overhead. Block sizes greater than 4K are supported up to a maximum of
18 64K.
19 Squashfs is intended for general read-only filesystem use, for archival
21 use (i.e. in cases where a .tar.gz file may be used), and in con‐
22 strained block device/memory systems (e.g. embedded systems) where low
23 overhead is needed.
24
27 Filesystem build options
28 -comp COMPRESSION
29 select COMPRESSION compression. Compressors available: gzip
30 (default), lzma (no kernel support), lzo, lz4 and xz.
31 -b BLOCK_SIZE
33 set data block to BLOCK_SIZE. Default 131072 bytes. Optionally K or
34 M can be used as a suffix to specify kilobytes or megabytes,
35 respectively.
36 -no-exports
38 don't make the filesystem exportable via NFS.
39 -no-sparse
41 don't detect sparse files.
42 -no-xattrs
44 don't store extended attributes.
45 -xattrs
47 store extended attributes (default).
48 -noI
50 do not compress inode table.
51 -noD
53 do not compress data blocks.
54 -noF
56 do not compress fragment blocks.
57 -noX
59 do not compress extended attributes.
60 -no-fragments
62 do not use fragments.
63 -always-use-fragments
65 use fragment blocks for files larger than block size.
66 -no-duplicates
68 do not perform duplicate checking.
69 -all-root
71 make all files owned by root.
72 -force-uid uid
74 set all file uids to uid.
75 -force-gid gid
77 set all file gids to gid.
78 -nopad
80 do not pad filesystem to a multiple of 4K.
81 -keep-as-directory
83 if one source directory is specified, create a root directory con‐
84 taining that directory, rather than the contents of the directory.
85 Filesystem filter options
88 -p PSEUDO_DEFINITION
89 Add pseudo file definition.
90 -pf PSEUDO_FILE
92 Add list of pseudo file definitions.
93 -sort SORT_FILE
95 sort files according to priorities in SORT_FILE. One file or dir
96 with priority per line. Priority -32768 to 32767, default priority
97 0.
98 -ef EXCLUDE_FILE
100 list of exclude dirs/files. One per line.
101 -wildcards
103 Allow extended shell wildcards (globbing) to be used in exclude
104 dirs/files
105 -regex
107 Allow POSIX regular expressions to be used in exclude dirs/files.
108 Filesystem append options
111 -noappend
112 do not append to existing filesystem.
113 -root-becomes NAME
115 when appending source files/directories, make the original root
116 become a subdirectory in the new root called NAME, rather than
117 adding the new source items to the original root.
118 Mksquashfs runtime options:
121 -version
122 print version, licence and copyright message.
123 -exit-on-error
125 treat normally ignored errors as fatal.
126 -recover NAME
128 recover filesystem data using recovery file NAME.
129 -no-recovery
131 don't generate a recovery file.
132 -info
134 print files written to filesystem.
135 -no-progress
137 don't display the progress bar.
138 -progress
140 display progress bar when using the -info option.
141 -processors NUMBER
143 Use NUMBER processors. By default will use number of processors
144 available.
145 -mem SIZE
147 Use SIZE physical memory. Optionally K or M can be used as a suffix
148 for kilobytes or megabytes, respectively. Default 25% of memory.
149 -read-queue SIZE
151 Deprecated. Use -mem instead.
152 -write-queue SIZE
154 Deprecated. Use -mem instead.
155 -fragment-queue SIZE
157 Deprecated. Use -mem instead.
158 Miscellaneous options
161 -root-owned
162 alternative name for -all-root.
163 -noInodeCompression
165 alternative name for -noI.
166 -noDataCompression
168 alternative name for -noD.
169 -noFragmentCompression
171 alternative name for -noF.
172 -noXattrCompression
174 alternative name for -noX.
175 -Xhelp
177 print compressor options for selected compressor
178 Compressors available and compressor specific options
181 gzip (default)
182 -Xcompression-level compression-level
184 compression-level should be 1 .. 9 (default 9)
185 -Xwindow-size window-size
187 window-size should be 8 .. 15 (default 15)
188 -Xstrategy strategy1,strategy2,...,strategyN
190 Compress using strategy1,strategy2,...,strategyN in turn and choose
191 the best compression. Available strategies: default, filtered,
192 huffman_only, run_length_encoded and fixed
193 lzmz (no options) (no kernel support)
195 lzo
197 -Xalgorithm algorithm
199 Where algorithm is one of: lzo1x_1, lzo1x_1_11, lzo1x_1_12,
200 lzo1x_1_15 or lzo1x_999. (default lzo1x_999)
201 -Xcompression-level compression-level
203 compression-level should be 1 .. 9 (default 8)
204 lz4
206 -Xhc
208 Compress using LZ4 High Compression
209 xz
211 -Xbcj filter1,filter2,...,filterN
213 Compress using filter1,filter2,...,filterN in turn (in addition to
214 no filter), and choose the best compression. Available filters:
215 x86, arm, armthumb, powerpc, sparc, ia64.
216 -Xdict-size DICT_SIZE
218 Use DICT_SIZE as the XZ dictionary size. The dictionary size can be
219 specified as a percentage of the block size, or as an absolute
220 value. The dictionary size must be less than or equal to the block
221 size and 8192 bytes or larger. It must also be storable in the xz
222 header as either 2^n or as 2^n+2^(n+1). Example dict-sizes are 75%,
223 50%, 37.5%, 25%, or 32K, 16K, 8K etc.
224 zstd
226 -Xcompression-level <compression-level>
228 <compression-level> should be 1 .. 22 (default 15)
229
233 unsquashfs(1)
234
237 More information about mksquashfs and the squashfs filesystem can be
238 found at <http://squashfs.sourceforge.net/>.
239
242 squashfs was written by Phillip Lougher <plougher@users.source‐
243 forge.net>.
244 This manual page was written by Daniel Baumann <daniel.bau‐
246 mann@progress-technologies.net>. With some updates for 4.3 for use with
247 Fedora.
2484.3 2014-05-13 MKSQUASHFS(1)