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3839e657 | 1 | .\" -*- nroff -*- |
a418d3ad TT |
2 | .\" Copyright 1993, 1994, 1995 by Theodore Ts'o. All Rights Reserved. |
3 | .\" This file may be copied under the terms of the GNU Public License. | |
98794d0e | 4 | .\" |
74becf3c | 5 | .TH MKE2FS 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@" |
3839e657 | 6 | .SH NAME |
e87bb84b | 7 | mke2fs \- create an ext2/ext3/ext4 file system |
3839e657 TT |
8 | .SH SYNOPSIS |
9 | .B mke2fs | |
10 | [ | |
11 | .B \-c | |
98794d0e | 12 | | |
3839e657 | 13 | .B \-l |
1e3472c5 | 14 | .I filename |
3839e657 TT |
15 | ] |
16 | [ | |
17 | .B \-b | |
1e3472c5 | 18 | .I block-size |
3839e657 TT |
19 | ] |
20 | [ | |
75dd3c47 TN |
21 | .B \-C |
22 | .I cluster-size | |
23 | ] | |
24 | [ | |
4407ea3b DW |
25 | .B \-d |
26 | .I root-directory | |
27 | ] | |
28 | [ | |
37c8db7b TT |
29 | .B \-D |
30 | ] | |
31 | [ | |
5e05541a TT |
32 | .B \-g |
33 | .I blocks-per-group | |
34 | ] | |
35 | [ | |
9ba40002 TT |
36 | .B \-G |
37 | .I number-of-groups | |
38 | ] | |
39 | [ | |
3839e657 | 40 | .B \-i |
1e3472c5 | 41 | .I bytes-per-inode |
3839e657 TT |
42 | ] |
43 | [ | |
067911ae AD |
44 | .B \-I |
45 | .I inode-size | |
46 | ] | |
47 | [ | |
85ef4ae8 | 48 | .B \-j |
dc2ec525 TT |
49 | ] |
50 | [ | |
51 | .B \-J | |
8ddaa66b | 52 | .I journal-options |
85ef4ae8 TT |
53 | ] |
54 | [ | |
5515e6b4 TT |
55 | .B \-N |
56 | .I number-of-inodes | |
57 | ] | |
58 | [ | |
a26ba650 | 59 | .B \-n |
2740156b TT |
60 | ] |
61 | [ | |
3839e657 | 62 | .B \-m |
1e3472c5 TT |
63 | .I reserved-blocks-percentage |
64 | ] | |
65 | [ | |
66 | .B \-o | |
67 | .I creator-os | |
3839e657 TT |
68 | ] |
69 | [ | |
98794d0e | 70 | .B \-O |
5c4c3876 | 71 | [^]\fIfeature\fR[,...] |
896938d5 TT |
72 | ] |
73 | [ | |
f3db3566 TT |
74 | .B \-q |
75 | ] | |
76 | [ | |
caf8ce4c TT |
77 | .B \-r |
78 | .I fs-revision-level | |
a29f4d30 TT |
79 | ] |
80 | [ | |
c6a44136 TT |
81 | .B \-E |
82 | .I extended-options | |
521e3685 TT |
83 | ] |
84 | [ | |
3839e657 TT |
85 | .B \-v |
86 | ] | |
f3db3566 | 87 | [ |
74becf3c TT |
88 | .B \-F |
89 | ] | |
90 | [ | |
1e3472c5 TT |
91 | .B \-L |
92 | .I volume-label | |
93 | ] | |
94 | [ | |
95 | .B \-M | |
96 | .I last-mounted-directory | |
97 | ] | |
98 | [ | |
f3db3566 TT |
99 | .B \-S |
100 | ] | |
818180cd | 101 | [ |
3d43836f TT |
102 | .B \-t |
103 | .I fs-type | |
104 | ] | |
105 | [ | |
50787ea2 | 106 | .B \-T |
3d43836f | 107 | .I usage-type |
50787ea2 TT |
108 | ] |
109 | [ | |
b0afdda1 TT |
110 | .B \-U |
111 | .I UUID | |
112 | ] | |
113 | [ | |
818180cd TT |
114 | .B \-V |
115 | ] | |
cd32129d DW |
116 | [ |
117 | .B \-e | |
118 | .I errors-behavior | |
119 | ] | |
2d291b3c DW |
120 | [ |
121 | .B \-z | |
122 | .I undo_file | |
123 | ] | |
1e3472c5 | 124 | .I device |
3839e657 | 125 | [ |
9ac2930c | 126 | .I fs-size |
3839e657 | 127 | ] |
48015ced | 128 | @JDEV@.sp |
8d641749 | 129 | @JDEV@.B "mke2fs \-O journal_dev" |
48015ced TT |
130 | @JDEV@[ |
131 | @JDEV@.B \-b | |
132 | @JDEV@.I block-size | |
133 | @JDEV@] | |
8d641749 | 134 | .\" No external-journal specific journal options yet (size is ignored) |
48015ced TT |
135 | .\" @JDEV@[ |
136 | .\" @JDEV@.B \-J | |
137 | .\" @JDEV@.I journal-options | |
138 | .\" @JDEV@] | |
139 | @JDEV@[ | |
140 | @JDEV@.B \-L | |
141 | @JDEV@.I volume-label | |
142 | @JDEV@] | |
143 | @JDEV@[ | |
144 | @JDEV@.B \-n | |
145 | @JDEV@] | |
146 | @JDEV@[ | |
147 | @JDEV@.B \-q | |
148 | @JDEV@] | |
149 | @JDEV@[ | |
150 | @JDEV@.B \-v | |
151 | @JDEV@] | |
8d641749 | 152 | @JDEV@.I external-journal |
2d15576d | 153 | @JDEV@[ |
9ac2930c | 154 | @JDEV@.I fs-size |
2d15576d | 155 | @JDEV@] |
3839e657 TT |
156 | .SH DESCRIPTION |
157 | .B mke2fs | |
e87bb84b | 158 | is used to create an ext2, ext3, or ext4 file system, usually in a disk |
9ac2930c TT |
159 | partition (or file) named by |
160 | .IR device . | |
161 | .PP | |
162 | The file system size is specified by | |
163 | .IR fs-size . | |
164 | If | |
165 | .I fs-size | |
166 | does not have a suffix, it is interpreted as power-of-two kilobytes, | |
167 | unless the | |
168 | .B \-b | |
169 | .I blocksize | |
170 | option is specified, in which case | |
171 | .I fs-size | |
172 | is interpreted as the number of | |
173 | .I blocksize | |
174 | blocks. If the fs-size is suffixed by 'k', 'm', 'g', 't' | |
175 | (either upper-case or lower-case), then it is interpreted in | |
176 | power-of-two kilobytes, megabytes, gigabytes, terabytes, etc. | |
177 | If | |
178 | .I fs-size | |
179 | is omitted, | |
3839e657 | 180 | .B mke2fs |
9ac2930c TT |
181 | will create the file system based on the device size. |
182 | .PP | |
183 | If | |
184 | .B mke2fs | |
185 | is run as | |
186 | .B mkfs.XXX | |
187 | (i.e., | |
188 | .BR mkfs.ext2 , | |
189 | .BR mkfs.ext3 , | |
190 | or | |
191 | .BR mkfs.ext4 ) | |
192 | the option | |
193 | .B \-t | |
194 | .I XXX | |
195 | is implied; so | |
0072f8de | 196 | .B mkfs.ext3 |
9ac2930c TT |
197 | will create a file system for use with ext3, |
198 | .B mkfs.ext4 | |
199 | will create a file system for use with ext4, and so on. | |
de7a86e2 | 200 | .PP |
e87bb84b | 201 | The defaults of the parameters for the newly created file system, if not |
de7a86e2 TT |
202 | overridden by the options listed below, are controlled by the |
203 | .B /etc/mke2fs.conf | |
204 | configuration file. See the | |
205 | .BR mke2fs.conf (5) | |
206 | manual page for more details. | |
3839e657 TT |
207 | .SH OPTIONS |
208 | .TP | |
caf8ce4c | 209 | .BI \-b " block-size" |
33b0356c JK |
210 | Specify the size of blocks in bytes. Valid block-size values are powers of two |
211 | from 1024 up to 65536 (however note that the kernel is able to mount only | |
e87bb84b | 212 | file systems with block-size smaller or equal to the system page size - 4k on |
51628724 | 213 | x86 systems, up to 64k on ppc64 or aarch64 depending on kernel configuration). |
e87bb84b TT |
214 | If omitted, block-size is heuristically determined by the file system size and |
215 | the expected usage of the file system (see the | |
06968e7e | 216 | .B \-T |
33b0356c | 217 | option). In most common cases, the default block size is 4k. If |
c5290fae | 218 | .I block-size |
eddf36ba | 219 | is preceded by a negative sign ('-'), then |
c6a44136 TT |
220 | .B mke2fs |
221 | will use heuristics to determine the | |
c5290fae | 222 | appropriate block size, with the constraint that the block size will be |
98794d0e | 223 | at least |
c5290fae TT |
224 | .I block-size |
225 | bytes. This is useful for certain hardware devices which require that | |
226 | the blocksize be a multiple of 2k. | |
3839e657 | 227 | .TP |
caf8ce4c | 228 | .B \-c |
3ed57c27 | 229 | Check the device for bad blocks before creating the file system. If |
98794d0e | 230 | this option is specified twice, then a slower read-write |
3ed57c27 | 231 | test is used instead of a fast read-only test. |
3839e657 | 232 | .TP |
0f680ee8 | 233 | .B \-C " cluster-size" |
e87bb84b | 234 | Specify the size of cluster in bytes for file systems using the bigalloc |
87cbb381 SD |
235 | feature. Valid cluster-size values range from 2 to 32768 times the |
236 | filesystem blocksize and must be a power of 2. The cluster-size can | |
237 | only be specified if the bigalloc feature is enabled. (See the | |
9518b297 TT |
238 | .B ext4 (5) |
239 | man page for more details about bigalloc.) The default cluster size if | |
240 | bigalloc is enabled is 16 times the block size. | |
0f680ee8 | 241 | .TP |
4407ea3b DW |
242 | .BI \-d " root-directory" |
243 | Copy the contents of the given directory into the root directory of the | |
e87bb84b | 244 | file system. |
4407ea3b | 245 | .TP |
37c8db7b TT |
246 | .B \-D |
247 | Use direct I/O when writing to the disk. This avoids mke2fs dirtying a | |
248 | lot of buffer cache memory, which may impact other applications running | |
249 | on a busy server. This option will cause mke2fs to run much more | |
250 | slowly, however, so there is a tradeoff to using direct I/O. | |
251 | .TP | |
cd32129d DW |
252 | .BI \-e " error-behavior" |
253 | Change the behavior of the kernel code when errors are detected. | |
e87bb84b | 254 | In all cases, a file system error will cause |
cd32129d | 255 | .BR e2fsck (8) |
e87bb84b | 256 | to check the file system on the next boot. |
cd32129d DW |
257 | .I error-behavior |
258 | can be one of the following: | |
259 | .RS 1.2i | |
260 | .TP 1.2i | |
261 | .B continue | |
262 | Continue normal execution. | |
263 | .TP | |
264 | .B remount-ro | |
e87bb84b | 265 | Remount file system read-only. |
cd32129d DW |
266 | .TP |
267 | .B panic | |
268 | Cause a kernel panic. | |
269 | .RE | |
270 | .TP | |
c6a44136 | 271 | .BI \-E " extended-options" |
e87bb84b | 272 | Set extended options for the file system. Extended options are comma |
c6a44136 | 273 | separated, and may take an argument using the equals ('=') sign. The |
a26ba650 | 274 | .B \-E |
98794d0e | 275 | option used to be |
a26ba650 | 276 | .B \-R |
98794d0e | 277 | in earlier versions of |
c6a44136 | 278 | .BR mke2fs . |
98794d0e | 279 | The |
a26ba650 | 280 | .B \-R |
b769aaec AD |
281 | option is still accepted for backwards compatibility, but is deprecated. |
282 | The following extended options are supported: | |
c6a44136 TT |
283 | .RS 1.2i |
284 | .TP | |
28887533 | 285 | .BI encoding= encoding-name |
e7236a94 | 286 | Enable the |
28887533 | 287 | .I casefold |
e7236a94 GKB |
288 | feature in the super block and set |
289 | .I encoding-name | |
290 | as the encoding to be used. If | |
291 | .I encoding-name | |
292 | is not specified, the encoding defined in | |
293 | .BR mke2fs.conf (5) | |
294 | is used. | |
295 | .TP | |
28887533 | 296 | .BI encoding_flags= encoding-flags |
e7236a94 GKB |
297 | Define parameters for file name character encoding operations. If a |
298 | flag is not changed using this parameter, its default value is used. | |
299 | .I encoding-flags | |
300 | should be a comma-separated lists of flags to be enabled. To disable a | |
301 | flag, add it to the list with the prefix "no". | |
302 | ||
303 | The only flag that can be set right now is | |
304 | .I strict | |
305 | which means that invalid strings should be rejected by the file system. | |
306 | In the default configuration, the | |
307 | .I strict | |
308 | flag is disabled. | |
309 | .TP | |
0f5eba75 AD |
310 | .BI mmp_update_interval= interval |
311 | Adjust the initial MMP update interval to | |
312 | .I interval | |
313 | seconds. Specifying an | |
314 | .I interval | |
315 | of 0 means to use the default interval. The specified interval must | |
316 | be less than 300 seconds. Requires that the | |
317 | .B mmp | |
318 | feature be enabled. | |
319 | .TP | |
0c17cb25 | 320 | .BI stride= stride-size |
e87bb84b | 321 | Configure the file system for a RAID array with |
0c17cb25 | 322 | .I stride-size |
e87bb84b | 323 | file system blocks. This is the number of blocks read or written to disk |
98794d0e | 324 | before moving to the next disk, which is sometimes referred to as the |
2ac7f066 | 325 | .I chunk size. |
e87bb84b | 326 | This mostly affects placement of file system metadata like bitmaps at |
a4396e9d | 327 | .B mke2fs |
98794d0e BS |
328 | time to avoid placing them on a single disk, which can hurt performance. |
329 | It may also be used by the block allocator. | |
0c17cb25 | 330 | .TP |
d4c0d8e5 | 331 | .BI stripe_width= stripe-width |
e87bb84b | 332 | Configure the file system for a RAID array with |
0c17cb25 | 333 | .I stripe-width |
e87bb84b | 334 | file system blocks per stripe. This is typically stride-size * N, where |
2ac7f066 | 335 | N is the number of data-bearing disks in the RAID (e.g. for RAID 5 there is one |
98794d0e | 336 | parity disk, so N will be the number of disks in the array minus 1). |
0c17cb25 TT |
337 | This allows the block allocator to prevent read-modify-write of the |
338 | parity in a RAID stripe if possible when the data is written. | |
c6a44136 | 339 | .TP |
88ee023b | 340 | .BI offset= offset |
e87bb84b | 341 | Create the file system at an offset from the beginning of the device or |
88ee023b TT |
342 | file. This can be useful when creating disk images for virtual machines. |
343 | .TP | |
c6a44136 TT |
344 | .BI resize= max-online-resize |
345 | Reserve enough space so that the block group descriptor table can grow | |
e87bb84b | 346 | to support a file system that has |
98794d0e BS |
347 | .I max-online-resize |
348 | blocks. | |
6cb27404 | 349 | .TP |
3b4a66cf | 350 | .B lazy_itable_init\fR[\fB= \fI<0 to disable, 1 to enable>\fR] |
a4396e9d | 351 | If enabled and the uninit_bg feature is enabled, the inode table will |
98794d0e | 352 | not be fully initialized by |
a4396e9d | 353 | .BR mke2fs . |
e87bb84b | 354 | This speeds up file system |
98794d0e | 355 | initialization noticeably, but it requires the kernel to finish |
e87bb84b | 356 | initializing the file system in the background when the file system is |
43781b94 | 357 | first mounted. If the option value is omitted, it defaults to 1 to |
6c54689f AD |
358 | enable lazy inode table zeroing. |
359 | .TP | |
360 | .B lazy_journal_init\fR[\fB= \fI<0 to disable, 1 to enable>\fR] | |
361 | If enabled, the journal inode will not be fully zeroed out by | |
362 | .BR mke2fs . | |
e87bb84b | 363 | This speeds up file system initialization noticeably, but carries some |
6c54689f AD |
364 | small risk if the system crashes before the journal has been overwritten |
365 | entirely one time. If the option value is omitted, it defaults to 1 to | |
366 | enable lazy journal inode zeroing. | |
a4396e9d | 367 | .TP |
bd2e72c5 SK |
368 | .B assume_storage_prezeroed\fR[\fB= \fI<0 to disable, 1 to enable>\fR] |
369 | If enabled, | |
370 | .BR mke2fs | |
371 | assumes that the storage device has been prezeroed, skips zeroing the journal | |
372 | and inode tables, and annotates the block group flags to signal that the inode | |
373 | table has been zeroed. | |
374 | .TP | |
6a9c8e0b | 375 | .B no_copy_xattrs |
8cec4acd TT |
376 | Normally |
377 | .B mke2fs | |
378 | will copy the extended attributes of the files in the directory | |
379 | hierarchy specified via the (optional) | |
380 | .B \-d | |
381 | option. This will disable the copy and leaves the files in the newly | |
382 | created file system without any extended attributes. | |
383 | .TP | |
65c6c3e0 TT |
384 | .BI num_backup_sb= <0|1|2> |
385 | If the | |
386 | .B sparse_super2 | |
387 | file system feature is enabled this option controls whether there will | |
388 | be 0, 1, or 2 backup superblocks created in the file system. | |
389 | .TP | |
3c6e91c5 TT |
390 | .B packed_meta_blocks\fR[\fB= \fI<0 to disable, 1 to enable>\fR] |
391 | Place the allocation bitmaps and the inode table at the beginning of the | |
392 | disk. This option requires that the flex_bg file system feature to be | |
393 | enabled in order for it to have effect, and will also create the journal | |
394 | at the beginning of the file system. This option is useful for flash | |
395 | devices that use SLC flash at the beginning of the disk. | |
396 | It also maximizes the range of contiguous data blocks, which | |
397 | can be useful for certain specialized use cases, such as supported | |
398 | Shingled Drives. | |
399 | .TP | |
dc9cc700 AD |
400 | .BI root_owner [=uid:gid] |
401 | Specify the numeric user and group ID of the root directory. If no UID:GID | |
402 | is specified, use the user and group ID of the user running \fBmke2fs\fR. | |
403 | In \fBmke2fs\fR 1.42 and earlier the UID and GID of the root directory were | |
404 | set by default to the UID and GID of the user running the mke2fs command. | |
405 | The \fBroot_owner=\fR option allows explicitly specifying these values, | |
406 | and avoid side-effects for users that do not expect the contents of the | |
e87bb84b | 407 | file system to change based on the user running \fBmke2fs\fR. |
dc9cc700 | 408 | .TP |
6cb27404 | 409 | .B test_fs |
e87bb84b TT |
410 | Set a flag in the file system superblock indicating that it may be |
411 | mounted using experimental kernel code, such as the ext4dev file system. | |
0bc85dfb | 412 | .TP |
818da4a9 JK |
413 | .BI orphan_file_size= size |
414 | Set size of the file for tracking unlinked but still open inodes and inodes | |
415 | with truncate in progress. Larger file allows for better scalability, reserving | |
416 | a few blocks per cpu is ideal. | |
417 | .TP | |
6a9c8e0b | 418 | .B discard |
0bc85dfb LC |
419 | Attempt to discard blocks at mkfs time (discarding blocks initially is useful |
420 | on solid state devices and sparse / thin-provisioned storage). When the device | |
421 | advertises that discard also zeroes data (any subsequent read after the discard | |
422 | and before write returns zero), then mark all not-yet-zeroed inode tables as | |
e87bb84b | 423 | zeroed. This significantly speeds up file system initialization. This is set |
0bc85dfb LC |
424 | as default. |
425 | .TP | |
6a9c8e0b | 426 | .B nodiscard |
855a77a1 | 427 | Do not attempt to discard blocks at mkfs time. |
9e8fcd6e | 428 | .TP |
6a9c8e0b | 429 | .B quotatype |
bc8f1ae5 TT |
430 | Specify the which quota types (usrquota, grpquota, prjquota) which |
431 | should be enabled in the created file system. The argument of this | |
432 | extended option should be a colon separated list. This option has | |
433 | effect only if the | |
9e8fcd6e | 434 | .B quota |
bc8f1ae5 TT |
435 | feature is set. The default quota types to be initialized if this |
436 | option is not specified is both user and group quotas. If the project | |
437 | feature is enabled that project quotas will be initialized as well. | |
c6a44136 TT |
438 | .RE |
439 | .TP | |
48015ced | 440 | .B \-F |
98794d0e | 441 | Force |
48015ced | 442 | .B mke2fs |
e87bb84b | 443 | to create a file system, even if the specified device is not a partition |
c16e610c | 444 | on a block special device, or if other parameters do not make sense. |
98794d0e | 445 | In order to force |
c16e610c | 446 | .B mke2fs |
e87bb84b | 447 | to create a file system even if the file system appears to be in use |
c16e610c AD |
448 | or is mounted (a truly dangerous thing to do), this option must be |
449 | specified twice. | |
48015ced | 450 | .TP |
5e05541a TT |
451 | .BI \-g " blocks-per-group" |
452 | Specify the number of blocks in a block group. There is generally no | |
98794d0e | 453 | reason for the user to ever set this parameter, as the default is optimal |
e87bb84b TT |
454 | for the file system. (For administrators who are creating |
455 | file systems on RAID arrays, it is preferable to use the | |
5e05541a TT |
456 | .I stride |
457 | RAID parameter as part of the | |
e28a1bca | 458 | .B \-E |
98794d0e | 459 | option rather than manipulating the number of blocks per group.) |
5e05541a | 460 | This option is generally used by developers who |
98794d0e | 461 | are developing test cases. |
0f680ee8 ZL |
462 | .IP |
463 | If the bigalloc feature is enabled, the | |
464 | .B \-g | |
465 | option will specify the number of clusters in a block group. | |
5e05541a | 466 | .TP |
9ba40002 | 467 | .BI \-G " number-of-groups" |
98794d0e | 468 | Specify the number of block groups that will be packed together to |
7a9f055f | 469 | create a larger virtual block group (or "flex_bg group") in an |
e87bb84b | 470 | ext4 file system. This improves meta-data locality and performance |
7a9f055f | 471 | on meta-data heavy workloads. The number of groups must be a power |
d04ad325 | 472 | of 2 and may only be specified if the |
7a9f055f | 473 | .B flex_bg |
e87bb84b | 474 | file system feature is enabled. |
9ba40002 | 475 | .TP |
caf8ce4c | 476 | .BI \-i " bytes-per-inode" |
98794d0e | 477 | Specify the bytes/inode ratio. |
3839e657 TT |
478 | .B mke2fs |
479 | creates an inode for every | |
480 | .I bytes-per-inode | |
98794d0e | 481 | bytes of space on the disk. The larger the |
caf8ce4c | 482 | .I bytes-per-inode |
48015ced | 483 | ratio, the fewer inodes will be created. This value generally shouldn't |
e87bb84b | 484 | be smaller than the blocksize of the file system, since in that case more |
98794d0e | 485 | inodes would be made than can ever be used. Be warned that it is not |
e87bb84b | 486 | possible to change this ratio on a file system after it is created, so be |
e2883e27 | 487 | careful deciding the correct value for this parameter. Note that resizing |
e87bb84b | 488 | a file system changes the number of inodes to maintain this ratio. |
067911ae AD |
489 | .TP |
490 | .BI \-I " inode-size" | |
98794d0e | 491 | Specify the size of each inode in bytes. |
886056bd | 492 | The |
067911ae | 493 | .I inode-size |
98794d0e | 494 | value must be a power of 2 larger or equal to 128. The larger the |
067911ae AD |
495 | .I inode-size |
496 | the more space the inode table will consume, and this reduces the usable | |
e87bb84b | 497 | space in the file system and can also negatively impact performance. |
886056bd | 498 | It is not |
e87bb84b | 499 | possible to change this value after the file system is created. |
886056bd | 500 | .IP |
4346f675 TT |
501 | File systems with an inode size of 128 bytes do not support timestamps |
502 | beyond January 19, 2038. Inodes which are 256 bytes or larger will | |
503 | support extended timestamps, project id's, and the ability to store some | |
504 | extended attributes in the inode table for improved performance. | |
886056bd TT |
505 | .IP |
506 | The default inode size is controlled by the | |
507 | .BR mke2fs.conf (5) | |
508 | file. In the | |
509 | .B mke2fs.conf | |
510 | file shipped with e2fsprogs, the default inode size is 256 bytes for | |
08079876 PH |
511 | all file systems, except for the GNU Hurd since it only supports |
512 | 128-byte inodes. | |
98794d0e | 513 | .TP |
48015ced | 514 | .B \-j |
e87bb84b | 515 | Create the file system with an ext3 journal. If the |
dc2ec525 | 516 | .B \-J |
48015ced | 517 | option is not specified, the default journal parameters will be used to |
e87bb84b TT |
518 | create an appropriately sized journal (given the size of the file system) |
519 | stored within the file system. Note that you must be using a kernel | |
48015ced | 520 | which has ext3 support in order to actually make use of the journal. |
dc2ec525 | 521 | .TP |
48015ced | 522 | .BI \-J " journal-options" |
dc2ec525 | 523 | Create the ext3 journal using options specified on the command-line. |
8ddaa66b TT |
524 | Journal options are comma |
525 | separated, and may take an argument using the equals ('=') sign. | |
48015ced TT |
526 | The following journal options are supported: |
527 | .RS 1.2i | |
dc2ec525 | 528 | .TP |
48015ced | 529 | .BI size= journal-size |
e87bb84b | 530 | Create an internal journal (i.e., stored inside the file system) of size |
98794d0e | 531 | .I journal-size |
8d641749 | 532 | megabytes. |
e87bb84b | 533 | The size of the journal must be at least 1024 file system blocks |
98794d0e | 534 | (i.e., 1MB if using 1k blocks, 4MB if using 4k blocks, etc.) |
e87bb84b | 535 | and may be no more than 10,240,000 file system blocks or half the total |
57cb2716 | 536 | file system size (whichever is smaller) |
b818205f | 537 | .TP |
06def17e HS |
538 | .BI fast_commit_size= fast-commit-size |
539 | Create an additional fast commit journal area of size | |
540 | .I fast-commit-size | |
541 | kilobytes. | |
542 | This option is only valid if | |
543 | .B fast_commit | |
544 | feature is enabled | |
545 | on the file system. If this option is not specified and if | |
546 | .B fast_commit | |
547 | feature is turned on, fast commit area size defaults to | |
548 | .I journal-size | |
549 | / 64 megabytes. The total size of the journal with | |
550 | .B fast_commit | |
551 | feature set is | |
552 | .I journal-size | |
553 | + ( | |
554 | .I fast-commit-size | |
555 | * 1024) megabytes. The total journal size may be no more than | |
e87bb84b | 556 | 10,240,000 file system blocks or half the total file system size |
06def17e HS |
557 | (whichever is smaller). |
558 | .TP | |
b818205f TT |
559 | .BI location =journal-location |
560 | Specify the location of the journal. The argument | |
561 | .I journal-location | |
562 | can either be specified as a block number, or if the number has a units | |
563 | suffix (e.g., 'M', 'G', etc.) interpret it as the offset from the | |
564 | beginning of the file system. | |
48015ced TT |
565 | @JDEV@.TP |
566 | @JDEV@.BI device= external-journal | |
e87bb84b | 567 | @JDEV@Attach the file system to the journal block device located on |
8d641749 TT |
568 | @JDEV@.IR external-journal . |
569 | @JDEV@The external | |
570 | @JDEV@journal must already have been created using the command | |
571 | @JDEV@.IP | |
2d15576d AD |
572 | @JDEV@.B mke2fs -O journal_dev |
573 | @JDEV@.I external-journal | |
8d641749 TT |
574 | @JDEV@.IP |
575 | @JDEV@Note that | |
576 | @JDEV@.I external-journal | |
577 | @JDEV@must have been created with the | |
e87bb84b | 578 | @JDEV@same block size as the new file system. |
3024d887 | 579 | @JDEV@In addition, while there is support for attaching |
e87bb84b | 580 | @JDEV@multiple file systems to a single external journal, |
98794d0e | 581 | @JDEV@the Linux kernel and |
3024d887 TT |
582 | @JDEV@.BR e2fsck (8) |
583 | @JDEV@do not currently support shared external journals yet. | |
2d15576d AD |
584 | @JDEV@.IP |
585 | @JDEV@Instead of specifying a device name directly, | |
586 | @JDEV@.I external-journal | |
587 | @JDEV@can also be specified by either | |
588 | @JDEV@.BI LABEL= label | |
589 | @JDEV@or | |
590 | @JDEV@.BI UUID= UUID | |
591 | @JDEV@to locate the external journal by either the volume label or UUID | |
592 | @JDEV@stored in the ext2 superblock at the start of the journal. Use | |
593 | @JDEV@.BR dumpe2fs (8) | |
594 | @JDEV@to display a journal device's volume label and UUID. See also the | |
595 | @JDEV@.B -L | |
596 | @JDEV@option of | |
597 | @JDEV@.BR tune2fs (8). | |
8d641749 TT |
598 | .RE |
599 | @JDEV@.IP | |
48015ced TT |
600 | @JDEV@Only one of the |
601 | @JDEV@.BR size " or " device | |
e87bb84b | 602 | @JDEV@options can be given for a file system. |
48015ced TT |
603 | .TP |
604 | .BI \-l " filename" | |
605 | Read the bad blocks list from | |
98794d0e | 606 | .IR filename . |
3ed57c27 | 607 | Note that the block numbers in the bad block list must be generated |
98794d0e BS |
608 | using the same block size as used by |
609 | .BR mke2fs . | |
610 | As a result, the | |
3ed57c27 | 611 | .B \-c |
98794d0e | 612 | option to |
3ed57c27 TT |
613 | .B mke2fs |
614 | is a much simpler and less error-prone method of checking a disk for bad | |
98794d0e | 615 | blocks before formatting it, as |
3ed57c27 TT |
616 | .B mke2fs |
617 | will automatically pass the correct parameters to the | |
618 | .B badblocks | |
619 | program. | |
48015ced | 620 | .TP |
6a7075df | 621 | .BI \-L " new-volume-label" |
e87bb84b | 622 | Set the volume label for the file system to |
6a7075df TT |
623 | .IR new-volume-label . |
624 | The maximum length of the | |
625 | volume label is 16 bytes. | |
48015ced TT |
626 | .TP |
627 | .BI \-m " reserved-blocks-percentage" | |
e87bb84b | 628 | Specify the percentage of the file system blocks reserved for |
029de632 | 629 | the super-user. This avoids fragmentation, and allows root-owned |
98794d0e | 630 | daemons, such as |
029de632 | 631 | .BR syslogd (8), |
98794d0e | 632 | to continue to function correctly after non-privileged processes are |
e87bb84b | 633 | prevented from writing to the file system. The default percentage |
029de632 | 634 | is 5%. |
dc2ec525 | 635 | .TP |
98794d0e | 636 | .BI \-M " last-mounted-directory" |
e87bb84b | 637 | Set the last mounted directory for the file system. This might be useful |
98794d0e | 638 | for the sake of utilities that key off of the last mounted directory to |
e87bb84b | 639 | determine where the file system should be mounted. |
85ef4ae8 | 640 | .TP |
caf8ce4c | 641 | .B \-n |
98794d0e BS |
642 | Causes |
643 | .B mke2fs | |
e87bb84b TT |
644 | to not actually create a file system, but display what it |
645 | would do if it were to create a file system. This can be used to | |
1f22ce34 | 646 | determine the location of the backup superblocks for a particular |
e87bb84b | 647 | file system, so long as the |
98794d0e BS |
648 | .B mke2fs |
649 | parameters that were passed when the | |
e87bb84b | 650 | file system was originally created are used again. (With the |
98794d0e | 651 | .B \-n |
1f22ce34 | 652 | option added, of course!) |
2740156b | 653 | .TP |
caf8ce4c | 654 | .BI \-N " number-of-inodes" |
98794d0e | 655 | Overrides the default calculation of the number of inodes that should be |
e87bb84b | 656 | reserved for the file system (which is based on the number of blocks and |
98794d0e | 657 | the |
caf8ce4c | 658 | .I bytes-per-inode |
98794d0e | 659 | ratio). This allows the user to specify the number |
5515e6b4 TT |
660 | of desired inodes directly. |
661 | .TP | |
48015ced | 662 | .BI \-o " creator-os" |
98794d0e | 663 | Overrides the default value of the "creator operating system" field of the |
e87bb84b | 664 | file system. The creator field is set by default to the name of the OS the |
583ccdc3 | 665 | .B mke2fs |
98794d0e | 666 | executable was compiled for. |
1e3472c5 | 667 | .TP |
5c4c3876 | 668 | .B "\-O \fR[^]\fIfeature\fR[,...]" |
e87bb84b TT |
669 | Create a file system with the given features (file system options), |
670 | overriding the default file system options. The features that are | |
9dc6ad1e TT |
671 | enabled by default are specified by the |
672 | .I base_features | |
673 | relation, either in the | |
98794d0e | 674 | .I [defaults] |
9dc6ad1e TT |
675 | section in the |
676 | .B /etc/mke2fs.conf | |
3d43836f | 677 | configuration file, |
98794d0e | 678 | or in the |
9dc6ad1e | 679 | .I [fs_types] |
98794d0e | 680 | subsections for the usage types as specified by the |
a26ba650 | 681 | .B \-T |
3d43836f TT |
682 | option, further modified by the |
683 | .I features | |
684 | relation found in the | |
98794d0e | 685 | .I [fs_types] |
e87bb84b | 686 | subsections for the file system and usage types. See the |
3d43836f TT |
687 | .BR mke2fs.conf (5) |
688 | manual page for more details. | |
e87bb84b | 689 | The file system type-specific configuration setting found in the |
9dc6ad1e TT |
690 | .I [fs_types] |
691 | section will override the global default found in | |
98794d0e | 692 | .IR [defaults] . |
48015ced | 693 | .sp |
e87bb84b | 694 | The file system feature set will be further edited |
98794d0e BS |
695 | using either the feature set specified by this option, |
696 | or if this option is not given, by the | |
9dc6ad1e | 697 | .I default_features |
e87bb84b | 698 | relation for the file system type being created, or in the |
98794d0e | 699 | .I [defaults] |
9dc6ad1e TT |
700 | section of the configuration file. |
701 | .sp | |
e87bb84b | 702 | The file system feature set is comprised of a list of features, separated |
9dc6ad1e | 703 | by commas, that are to be enabled. To disable a feature, simply |
5c4c3876 | 704 | prefix the feature name with a caret ('^') character. |
3c22bf7e | 705 | Features with dependencies will not be removed successfully. |
e87bb84b | 706 | The pseudo-file system feature "none" will clear all file system features. |
4727c67d | 707 | .TP |
3c22bf7e TT |
708 | For more information about the features which can be set, please see |
709 | the manual page | |
710 | .BR ext4 (5). | |
1e3472c5 | 711 | .TP |
8d641749 | 712 | .B \-q |
98794d0e | 713 | Quiet execution. Useful if |
8d641749 TT |
714 | .B mke2fs |
715 | is run in a script. | |
716 | .TP | |
48015ced | 717 | .BI \-r " revision" |
e87bb84b TT |
718 | Set the file system revision for the new file system. Note that 1.2 |
719 | kernels only support revision 0 file systems. The default is to | |
720 | create revision 1 file systems. | |
a29f4d30 | 721 | .TP |
caf8ce4c | 722 | .B \-S |
a6eeac1c AD |
723 | Write superblock and group descriptors only. This is an extreme |
724 | measure to be taken only in the very unlikely case that all of | |
f3db3566 | 725 | the superblock and backup superblocks are corrupted, and a last-ditch |
a6eeac1c | 726 | recovery method is desired by experienced users. It causes |
583ccdc3 | 727 | .B mke2fs |
a6eeac1c AD |
728 | to reinitialize the superblock and group descriptors, while not |
729 | touching the inode table and the block and inode bitmaps. The | |
f3db3566 TT |
730 | .B e2fsck |
731 | program should be run immediately after this option is used, and there | |
a6eeac1c AD |
732 | is no guarantee that any data will be salvageable. Due to the wide |
733 | variety of possible options to | |
6a9c8e0b | 734 | .B mke2fs |
a7dc56f4 | 735 | that affect the on-disk layout, it is critical to specify exactly |
a6eeac1c | 736 | the same format options, such as blocksize, fs-type, feature flags, and |
e87bb84b TT |
737 | other tunables when using this option, or the file system will be further |
738 | corrupted. In some cases, such as file systems that have been resized, | |
a6eeac1c | 739 | or have had features enabled after format time, it is impossible to |
e87bb84b | 740 | overwrite all of the superblocks correctly, and at least some file system |
a6eeac1c | 741 | corruption will occur. It is best to run this on a full copy of the |
e87bb84b | 742 | file system so other options can be tried if this doesn't work. |
8d641749 TT |
743 | .\" .TP |
744 | .\" .BI \-t " test" | |
745 | .\" Check the device for bad blocks before creating the file system | |
746 | .\" using the specified test. | |
818180cd | 747 | .TP |
3d43836f | 748 | .BI \-t " fs-type" |
e87bb84b | 749 | Specify the file system type (i.e., ext2, ext3, ext4, etc.) that is |
4727c67d | 750 | to be created. |
98794d0e BS |
751 | If this option is not specified, |
752 | .B mke2fs | |
753 | will pick a default either via how | |
754 | the command was run (for example, using a name of the form mkfs.ext2, | |
3d43836f | 755 | mkfs.ext3, etc.) or via a default as defined by the |
626a2e74 | 756 | .B /etc/mke2fs.conf |
e87bb84b | 757 | file. This option controls which file system options are used by |
08c8b1ab TT |
758 | default, based on the |
759 | .B fstypes | |
760 | configuration stanza in | |
626a2e74 | 761 | .BR /etc/mke2fs.conf . |
08c8b1ab TT |
762 | .sp |
763 | If the | |
764 | .B \-O | |
e87bb84b TT |
765 | option is used to explicitly add or remove file system options that |
766 | should be set in the newly created file system, the | |
767 | resulting file system may not be supported by the requested | |
08c8b1ab | 768 | .IR fs-type . |
b7150807 | 769 | (e.g., "\fBmke2fs \-t ext3 \-O extent /dev/sdXX\fR" will create a |
e87bb84b | 770 | file system that is not supported by the ext3 implementation as found in |
93aa0246 | 771 | the Linux kernel; and "\fBmke2fs \-t ext3 \-O ^has_journal /dev/hdXX\fR" |
e87bb84b TT |
772 | will create a file system that does not have a journal and hence will not |
773 | be supported by the ext3 file system code in the Linux kernel.) | |
3d43836f TT |
774 | .TP |
775 | .BI \-T " usage-type[,...]" | |
e87bb84b | 776 | Specify how the file system is going to be used, so that |
98794d0e | 777 | .B mke2fs |
e87bb84b | 778 | can choose optimal file system parameters for that use. The usage |
3d43836f | 779 | types that are supported are defined in the configuration file |
626a2e74 | 780 | .BR /etc/mke2fs.conf . |
3d43836f TT |
781 | The user may specify one or more usage types |
782 | using a comma separated list. | |
783 | .sp | |
784 | If this option is is not specified, | |
785 | .B mke2fs | |
e87bb84b TT |
786 | will pick a single default usage type based on the size of the file system to |
787 | be created. If the file system size is less than 3 megabytes, | |
a4396e9d | 788 | .B mke2fs |
e87bb84b | 789 | will use the file system type |
3d43836f | 790 | .IR floppy . |
e87bb84b | 791 | If the file system size is greater than or equal to 3 but less than |
3d43836f TT |
792 | 512 megabytes, |
793 | .BR mke2fs (8) | |
e87bb84b | 794 | will use the file system type |
3d43836f | 795 | .IR small . |
e87bb84b | 796 | If the file system size is greater than or equal to 4 terabytes but less than |
9a2767ff NK |
797 | 16 terabytes, |
798 | .BR mke2fs (8) | |
e87bb84b | 799 | will use the file system type |
9a2767ff | 800 | .IR big . |
e87bb84b | 801 | If the file system size is greater than or equal to 16 terabytes, |
9a2767ff | 802 | .BR mke2fs (8) |
e87bb84b | 803 | will use the file system type |
9a2767ff | 804 | .IR huge . |
3d43836f TT |
805 | Otherwise, |
806 | .BR mke2fs (8) | |
e87bb84b | 807 | will use the default file system type |
3d43836f | 808 | .IR default . |
48015ced | 809 | .TP |
b0afdda1 | 810 | .BI \-U " UUID" |
e87bb84b | 811 | Set the universally unique identifier (UUID) of the file system to |
665ebf37 DD |
812 | .IR UUID . |
813 | The format of the UUID is a series of hex digits separated by hyphens, | |
814 | like this: | |
815 | "c1b9d5a2-f162-11cf-9ece-0020afc76f16". | |
816 | The | |
817 | .I UUID | |
818 | parameter may also be one of the following: | |
819 | .RS 1.2i | |
820 | .TP | |
821 | .I clear | |
e87bb84b | 822 | clear the file system UUID |
665ebf37 DD |
823 | .TP |
824 | .I random | |
825 | generate a new randomly-generated UUID | |
826 | .TP | |
827 | .I time | |
828 | generate a new time-based UUID | |
829 | .RE | |
b0afdda1 | 830 | .TP |
48015ced TT |
831 | .B \-v |
832 | Verbose execution. | |
50787ea2 | 833 | .TP |
caf8ce4c | 834 | .B \-V |
98794d0e | 835 | Print the version number of |
818180cd TT |
836 | .B mke2fs |
837 | and exit. | |
2d291b3c DW |
838 | .TP |
839 | .BI \-z " undo_file" | |
840 | Before overwriting a file system block, write the old contents of the block to | |
841 | an undo file. This undo file can be used with e2undo(8) to restore the old | |
842 | contents of the file system should something go wrong. If the empty string is | |
843 | passed as the undo_file argument, the undo file will be written to a file named | |
844 | mke2fs-\fIdevice\fR.e2undo in the directory specified via the | |
845 | \fIE2FSPROGS_UNDO_DIR\fR environment variable or the \fIundo_dir\fR directive | |
846 | in the configuration file. | |
847 | ||
848 | WARNING: The undo file cannot be used to recover from a power or system crash. | |
5182ad4c NK |
849 | .SH ENVIRONMENT |
850 | .TP | |
6a9c8e0b | 851 | .B MKE2FS_SYNC |
5182ad4c NK |
852 | If set to non-zero integer value, its value is used to determine how often |
853 | .BR sync (2) | |
854 | is called during inode table initialization. | |
855 | .TP | |
6a9c8e0b | 856 | .B MKE2FS_CONFIG |
5182ad4c NK |
857 | Determines the location of the configuration file (see |
858 | .BR mke2fs.conf (5)). | |
859 | .TP | |
6a9c8e0b | 860 | .B MKE2FS_FIRST_META_BG |
5182ad4c NK |
861 | If set to non-zero integer value, its value is used to determine first meta |
862 | block group. This is mostly for debugging purposes. | |
863 | .TP | |
6a9c8e0b | 864 | .B MKE2FS_DEVICE_SECTSIZE |
75dd3c47 TN |
865 | If set to non-zero integer value, its value is used to determine logical |
866 | sector size of the | |
867 | .IR device . | |
868 | .TP | |
6a9c8e0b | 869 | .B MKE2FS_DEVICE_PHYS_SECTSIZE |
5182ad4c NK |
870 | If set to non-zero integer value, its value is used to determine physical |
871 | sector size of the | |
872 | .IR device . | |
873 | .TP | |
6a9c8e0b | 874 | .B MKE2FS_SKIP_CHECK_MSG |
e87bb84b | 875 | If set, do not show the message of file system automatic check caused by |
5182ad4c | 876 | mount count or check interval. |
3839e657 TT |
877 | .SH AUTHOR |
878 | This version of | |
879 | .B mke2fs | |
a418d3ad | 880 | has been written by Theodore Ts'o <tytso@mit.edu>. |
3839e657 TT |
881 | .SH AVAILABILITY |
882 | .B mke2fs | |
98794d0e | 883 | is part of the e2fsprogs package and is available from |
348e43dc | 884 | http://e2fsprogs.sourceforge.net. |
3839e657 | 885 | .SH SEE ALSO |
9dc6ad1e | 886 | .BR mke2fs.conf (5), |
e72a9ba3 | 887 | .BR badblocks (8), |
3839e657 TT |
888 | .BR dumpe2fs (8), |
889 | .BR e2fsck (8), | |
3c22bf7e TT |
890 | .BR tune2fs (8), |
891 | .BR ext4 (5) |