1MKSQUASHFS(1) create and append squashfs filesystems MKSQUASHFS(1)
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6 mksquashfs - tool to create and append to squashfs filesystems
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10 mksquashfs SOURCE [SOURCE2 ...] DESTINATION [OPTIONS]
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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.
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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 -all-time time
87 32 bit integer indicating seconds since the epoch (1970-01-01) used
88 for the timestamp for all files. The SOURCE_DATE_EPOCH environment
89 variable can also be used.
90 Filesystem filter options
93 -p PSEUDO_DEFINITION
94 Add pseudo file definition.
95 -pf PSEUDO_FILE
97 Add list of pseudo file definitions.
98 -sort SORT_FILE
100 sort files according to priorities in SORT_FILE. One file or dir
101 with priority per line. Priority -32768 to 32767, default priority
102 0.
103 -ef EXCLUDE_FILE
105 list of exclude dirs/files. One per line.
106 -wildcards
108 Allow extended shell wildcards (globbing) to be used in exclude
109 dirs/files
110 -regex
112 Allow POSIX regular expressions to be used in exclude dirs/files.
113 Filesystem append options
116 -noappend
117 do not append to existing filesystem.
118 -root-becomes NAME
120 when appending source files/directories, make the original root
121 become a subdirectory in the new root called NAME, rather than
122 adding the new source items to the original root.
123 Mksquashfs runtime options:
126 -version
127 print version, licence and copyright message.
128 -exit-on-error
130 treat normally ignored errors as fatal.
131 -recover NAME
133 recover filesystem data using recovery file NAME.
134 -no-recovery
136 don't generate a recovery file.
137 -info
139 print files written to filesystem.
140 -no-progress
142 don't display the progress bar.
143 -progress
145 display progress bar when using the -info option.
146 -processors NUMBER
148 Use NUMBER processors. By default will use number of processors
149 available.
150 -mem SIZE
152 Use SIZE physical memory. Optionally K or M can be used as a suffix
153 for kilobytes or megabytes, respectively. Default 25% of memory.
154 -read-queue SIZE
156 Deprecated. Use -mem instead.
157 -write-queue SIZE
159 Deprecated. Use -mem instead.
160 -fragment-queue SIZE
162 Deprecated. Use -mem instead.
163 -mkfs-time time
165 32 bit integer indicating seconds since the epoch (1970-01-01). The
166 SOURCE_DATE_EPOCH environment variable can also be used.
167 -not-reproducible
169 This option tells Mksquashfs that the files do not have to be
170 strictly ordered.
171 Miscellaneous options
174 -root-owned
175 alternative name for -all-root.
176 -noInodeCompression
178 alternative name for -noI.
179 -noDataCompression
181 alternative name for -noD.
182 -noFragmentCompression
184 alternative name for -noF.
185 -noXattrCompression
187 alternative name for -noX.
188 -Xhelp
190 print compressor options for selected compressor
191 Compressors available and compressor specific options
194 gzip (default)
195 -Xcompression-level compression-level
197 compression-level should be 1 .. 9 (default 9)
198 -Xwindow-size window-size
200 window-size should be 8 .. 15 (default 15)
201 -Xstrategy strategy1,strategy2,...,strategyN
203 Compress using strategy1,strategy2,...,strategyN in turn and choose
204 the best compression. Available strategies: default, filtered,
205 huffman_only, run_length_encoded and fixed
206 lzmz (no options) (no kernel support)
208 lzo
210 -Xalgorithm algorithm
212 Where algorithm is one of: lzo1x_1, lzo1x_1_11, lzo1x_1_12,
213 lzo1x_1_15 or lzo1x_999. (default lzo1x_999)
214 -Xcompression-level compression-level
216 compression-level should be 1 .. 9 (default 8)
217 lz4
219 -Xhc
221 Compress using LZ4 High Compression
222 xz
224 -Xbcj filter1,filter2,...,filterN
226 Compress using filter1,filter2,...,filterN in turn (in addition to
227 no filter), and choose the best compression. Available filters:
228 x86, arm, armthumb, powerpc, sparc, ia64.
229 -Xdict-size DICT_SIZE
231 Use DICT_SIZE as the XZ dictionary size. The dictionary size can be
232 specified as a percentage of the block size, or as an absolute
233 value. The dictionary size must be less than or equal to the block
234 size and 8192 bytes or larger. It must also be storable in the xz
235 header as either 2^n or as 2^n+2^(n+1). Example dict-sizes are 75%,
236 50%, 37.5%, 25%, or 32K, 16K, 8K etc.
237 zstd
239 -Xcompression-level <compression-level>
241 <compression-level> should be 1 .. 22 (default 15)
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246 unsquashfs(1)
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250 More information about mksquashfs and the squashfs filesystem can be
251 found at <http://squashfs.sourceforge.net/>.
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255 squashfs was written by Phillip Lougher <plougher@users.source‐
256 forge.net>.
257 This manual page was written by Daniel Baumann <daniel.bau‐
259 mann@progress-technologies.net>. With some updates for 4.4 for use with
260 Fedora.
2614.4 2020-05-12 MKSQUASHFS(1)