1mkfs.xfs(8) System Manager's Manual mkfs.xfs(8)
2
6 mkfs.xfs - construct an XFS filesystem
7
9 mkfs.xfs [ -b block_size_options ] [ -m global_metadata_options ] [ -d
10 data_section_options ] [ -f ] [ -i inode_options ] [ -l log_sec‐
11 tion_options ] [ -n naming_options ] [ -p protofile ] [ -q ] [ -r real‐
12 time_section_options ] [ -s sector_size_options ] [ -L label ] [ -N ] [
13 -K ] device
14 mkfs.xfs -V
15
17 mkfs.xfs constructs an XFS filesystem by writing on a special file
18 using the values found in the arguments of the command line. It is
19 invoked automatically by mkfs(8) when it is given the -t xfs option.
20 In its simplest (and most commonly used form), the size of the filesys‐
22 tem is determined from the disk driver. As an example, to make a
23 filesystem with an internal log on the first partition on the first
24 SCSI disk, use:
25 mkfs.xfs /dev/sda1
27 The metadata log can be placed on another device to reduce the number
29 of disk seeks. To create a filesystem on the first partition on the
30 first SCSI disk with a 10MiB log located on the first partition on the
31 second SCSI disk, use:
32 mkfs.xfs -l logdev=/dev/sdb1,size=10m /dev/sda1
34 Each of the option elements in the argument list above can be given as
36 multiple comma-separated suboptions if multiple suboptions apply to the
37 same option. Equivalently, each main option can be given multiple
38 times with different suboptions. For example, -l internal,size=10m and
39 -l internal -l size=10m are equivalent.
40 In the descriptions below, sizes are given in sectors, bytes, blocks,
42 kilobytes, megabytes, gigabytes, etc. Sizes are treated as hexadecimal
43 if prefixed by 0x or 0X, octal if prefixed by 0, or decimal otherwise.
44 The following lists possible multiplication suffixes:
45 s - multiply by sector size (default = 512, see -s option
46 below).
47 b - multiply by filesystem block size (default = 4K, see -b
48 option below).
49 k - multiply by one kilobyte (1,024 bytes).
50 m - multiply by one megabyte (1,048,576 bytes).
51 g - multiply by one gigabyte (1,073,741,824 bytes).
52 t - multiply by one terabyte (1,099,511,627,776 bytes).
53 p - multiply by one petabyte (1,024 terabytes).
54 e - multiply by one exabyte (1,048,576 terabytes).
55 When specifying parameters in units of sectors or filesystem blocks,
57 the -s option or the -b option may be used to specify the size of the
58 sector or block. If the size of the block or sector is not specified,
59 the default sizes (block: 4KiB, sector: 512B) will be used.
60 Many feature options allow an optional argument of 0 or 1, to explic‐
62 itly disable or enable the functionality.
63
65 -b block_size_options
66 This option specifies the fundamental block size of the filesys‐
67 tem. The valid block_size_option is:
68 size=value
70 The filesystem block size is specified with a value
71 in bytes. The default value is 4096 bytes (4 KiB),
72 the minimum is 512, and the maximum is 65536 (64
73 KiB).
74 Although mkfs.xfs will accept any of these values
76 and create a valid filesystem, XFS on Linux can only
77 mount filesystems with pagesize or smaller blocks.
78 -m global_metadata_options
80 These options specify metadata format options that either apply
81 to the entire filesystem or aren't easily characterised by a
82 specific functionality group. The valid global_metadata_options
83 are:
84 crc=value
86 This is used to create a filesystem which maintains
87 and checks CRC information in all metadata objects
88 on disk. The value is either 0 to disable the fea‐
89 ture, or 1 to enable the use of CRCs.
90 CRCs enable enhanced error detection due to hardware
92 issues, whilst the format changes also improves
93 crash recovery algorithms and the ability of various
94 tools to validate and repair metadata corruptions
95 when they are found. The CRC algorithm used is
96 CRC32c, so the overhead is dependent on CPU archi‐
97 tecture as some CPUs have hardware acceleration of
98 this algorithm. Typically the overhead of calculat‐
99 ing and checking the CRCs is not noticeable in nor‐
100 mal operation.
101 By default, mkfs.xfs will enable metadata CRCs.
103 finobt=value
105 This option enables the use of a separate free inode
106 btree index in each allocation group. The value is
107 either 0 to disable the feature, or 1 to create a
108 free inode btree in each allocation group.
109 The free inode btree mirrors the existing allocated
111 inode btree index which indexes both used and free
112 inodes. The free inode btree does not index used
113 inodes, allowing faster, more consistent inode allo‐
114 cation performance as filesystems age.
115 By default, mkfs.xfs will create free inode btrees
117 for filesystems created with the (default) -m crc=1
118 option set. When the option -m crc=0 is used, the
119 free inode btree feature is not supported and is
120 disabled.
121 uuid=value
123 Use the given value as the filesystem UUID for the
124 newly created filesystem. The default is to gener‐
125 ate a random UUID.
126 rmapbt=value
128 This option enables the creation of a reverse-map‐
129 ping btree index in each allocation group. The
130 value is either 0 to disable the feature, or 1 to
131 create the btree.
132 The reverse mapping btree maps filesystem blocks to
134 the owner of the filesystem block. Most of the map‐
135 pings will be to an inode number and an offset,
136 though there will also be mappings to filesystem
137 metadata. This secondary metadata can be used to
138 validate the primary metadata or to pinpoint exactly
139 which data has been lost when a disk error occurs.
140 By default, mkfs.xfs will not create reverse mapping
142 btrees. This feature is only available for filesys‐
143 tems created with the (default) -m crc=1 option set.
144 When the option -m crc=0 is used, the reverse map‐
145 ping btree feature is not supported and is disabled.
146 reflink=value
148 This option enables the use of a separate reference
149 count btree index in each allocation group. The
150 value is either 0 to disable the feature, or 1 to
151 create a reference count btree in each allocation
152 group.
153 The reference count btree enables the sharing of
155 physical extents between the data forks of different
156 files, which is commonly known as "reflink". Unlike
157 traditional Unix filesystems which assume that every
158 inode and logical block pair map to a unique physi‐
159 cal block, a reflink-capable XFS filesystem removes
160 the uniqueness requirement, allowing up to four bil‐
161 lion arbitrary inode/logical block pairs to map to a
162 physical block. If a program tries to write to a
163 multiply-referenced block in a file, the write will
164 be redirected to a new block, and that file's logi‐
165 cal-to-physical mapping will be changed to the new
166 block ("copy on write"). This feature enables the
167 creation of per-file snapshots and deduplication.
168 It is only available for the data forks of regular
169 files.
170 By default, mkfs.xfs will create reference count
172 btrees and therefore will enable the reflink fea‐
173 ture. This feature is only available for filesys‐
174 tems created with the (default) -m crc=1 option set.
175 When the option -m crc=0 is used, the reference
176 count btree feature is not supported and reflink is
177 disabled.
178 Note: the filesystem DAX mount option ( -o dax ) is
180 incompatible with reflink-enabled XFS filesystems.
181 To use filesystem DAX with XFS, specify the -m
182 reflink=0 option to mkfs.xfs to disable the reflink
183 feature.
184 -d data_section_options
186 These options specify the location, size, and other parameters
187 of the data section of the filesystem. The valid data_sec‐
188 tion_options are:
189 agcount=value
191 This is used to specify the number of allocation
192 groups. The data section of the filesystem is
193 divided into allocation groups to improve the per‐
194 formance of XFS. More allocation groups imply that
195 more parallelism can be achieved when allocating
196 blocks and inodes. The minimum allocation group size
197 is 16 MiB; the maximum size is just under 1 TiB.
198 The data section of the filesystem is divided into
199 value allocation groups (default value is scaled
200 automatically based on the underlying device size).
201 agsize=value
203 This is an alternative to using the agcount subop‐
204 tion. The value is the desired size of the alloca‐
205 tion group expressed in bytes (usually using the m
206 or g suffixes). This value must be a multiple of
207 the filesystem block size, and must be at least
208 16MiB, and no more than 1TiB, and may be automati‐
209 cally adjusted to properly align with the stripe
210 geometry. The agcount and agsize suboptions are
211 mutually exclusive.
212 cowextsize=value
214 Set the copy-on-write extent size hint on all inodes
215 created by mkfs.xfs. The value must be provided in
216 units of filesystem blocks. If the value is zero,
217 the default value (currently 32 blocks) will be
218 used. Directories will pass on this hint to newly
219 created children.
220 name=value
222 This can be used to specify the name of the special
223 file containing the filesystem. In this case, the
224 log section must be specified as internal (with a
225 size, see the -l option below) and there can be no
226 real-time section.
227 file[=value]
229 This is used to specify that the file given by the
230 name suboption is a regular file. The value is
231 either 0 or 1, with 1 signifying that the file is
232 regular. This suboption is used only to make a
233 filesystem image. If the value is omitted then 1 is
234 assumed.
235 size=value
237 This is used to specify the size of the data sec‐
238 tion. This suboption is required if -d file[=1] is
239 given. Otherwise, it is only needed if the filesys‐
240 tem should occupy less space than the size of the
241 special file.
242 sunit=value
244 This is used to specify the stripe unit for a RAID
245 device or a logical volume. The value has to be
246 specified in 512-byte block units. Use the su subop‐
247 tion to specify the stripe unit size in bytes. This
248 suboption ensures that data allocations will be
249 stripe unit aligned when the current end of file is
250 being extended and the file size is larger than
251 512KiB. Also inode allocations and the internal log
252 will be stripe unit aligned.
253 su=value
255 This is an alternative to using sunit. The su sub‐
256 option is used to specify the stripe unit for a RAID
257 device or a striped logical volume. The value has to
258 be specified in bytes, (usually using the m or g
259 suffixes). This value must be a multiple of the
260 filesystem block size.
261 swidth=value
263 This is used to specify the stripe width for a RAID
264 device or a striped logical volume. The value has to
265 be specified in 512-byte block units. Use the sw
266 suboption to specify the stripe width size in bytes.
267 This suboption is required if -d sunit has been
268 specified and it has to be a multiple of the -d
269 sunit suboption.
270 sw=value
272 suboption is an alternative to using swidth. The sw
273 suboption is used to specify the stripe width for a
274 RAID device or striped logical volume. The value is
275 expressed as a multiplier of the stripe unit, usu‐
276 ally the same as the number of stripe members in the
277 logical volume configuration, or data disks in a
278 RAID device.
279 When a filesystem is created on a logical volume
281 device, mkfs.xfs will automatically query the logi‐
282 cal volume for appropriate sunit and swidth values.
283 noalign
285 This option disables automatic geometry detection
286 and creates the filesystem without stripe geometry
287 alignment even if the underlying storage device pro‐
288 vides this information.
289 rtinherit=value
291 If set, all inodes created by mkfs.xfs will be cre‐
292 ated with the realtime flag set. Directories will
293 pass on this flag to newly created children.
294 projinherit=value
296 All inodes created by mkfs.xfs will be assigned this
297 project quota id. Directories will pass on the
298 project id to newly created children.
299 extszinherit=value
301 All inodes created by mkfs.xfs will have this extent
302 size hint applied. The value must be provided in
303 units of filesystem blocks. Directories will pass
304 on this hint to newly created children.
305 -f Force overwrite when an existing filesystem is detected on the
307 device. By default, mkfs.xfs will not write to the device if it
308 suspects that there is a filesystem or partition table on the
309 device already.
310 -i inode_options
312 This option specifies the inode size of the filesystem, and
313 other inode allocation parameters. The XFS inode contains a
314 fixed-size part and a variable-size part. The variable-size
315 part, whose size is affected by this option, can contain: direc‐
316 tory data, for small directories; attribute data, for small
317 attribute sets; symbolic link data, for small symbolic links;
318 the extent list for the file, for files with a small number of
319 extents; and the root of a tree describing the location of
320 extents for the file, for files with a large number of extents.
321 The valid inode_options are:
323 size=value | perblock=value
325 The inode size is specified either as a value in
326 bytes with size= or as the number fitting in a
327 filesystem block with perblock=. The minimum (and
328 default) value is 256 bytes without crc, 512 bytes
329 with crc enabled. The maximum value is 2048 (2 KiB)
330 subject to the restriction that the inode size can‐
331 not exceed one half of the filesystem block size.
332 XFS uses 64-bit inode numbers internally; however,
334 the number of significant bits in an inode number is
335 affected by filesystem geometry. In practice,
336 filesystem size and inode size are the predominant
337 factors. The Linux kernel (on 32 bit hardware plat‐
338 forms) and most applications cannot currently handle
339 inode numbers greater than 32 significant bits, so
340 if no inode size is given on the command line,
341 mkfs.xfs will attempt to choose a size such that
342 inode numbers will be < 32 bits. If an inode size
343 is specified, or if a filesystem is sufficiently
344 large, mkfs.xfs will warn if this will create inode
345 numbers > 32 significant bits.
346 maxpct=value
348 This specifies the maximum percentage of space in
349 the filesystem that can be allocated to inodes. The
350 default value is 25% for filesystems under 1TB, 5%
351 for filesystems under 50TB and 1% for filesystems
352 over 50TB.
353 In the default inode allocation mode, inode blocks
355 are chosen such that inode numbers will not exceed
356 32 bits, which restricts the inode blocks to the
357 lower portion of the filesystem. The data block
358 allocator will avoid these low blocks to accommodate
359 the specified maxpct, so a high value may result in
360 a filesystem with nothing but inodes in a signifi‐
361 cant portion of the lower blocks of the filesystem.
362 (This restriction is not present when the filesystem
363 is mounted with the inode64 option on 64-bit plat‐
364 forms).
365 Setting the value to 0 means that essentially all of
367 the filesystem can become inode blocks, subject to
368 inode32 restrictions.
369 This value can be modified with xfs_growfs(8).
371 align[=value]
373 This is used to specify that inode allocation is or
374 is not aligned. The value is either 0 or 1, with 1
375 signifying that inodes are allocated aligned. If
376 the value is omitted, 1 is assumed. The default is
377 that inodes are aligned. Aligned inode access is
378 normally more efficient than unaligned access;
379 alignment must be established at the time the
380 filesystem is created, since inodes are allocated at
381 that time. This option can be used to turn off
382 inode alignment when the filesystem needs to be
383 mountable by a version of IRIX that does not have
384 the inode alignment feature (any release of IRIX
385 before 6.2, and IRIX 6.2 without XFS patches).
386 attr=value
388 This is used to specify the version of extended
389 attribute inline allocation policy to be used. By
390 default, this is 2, which uses an efficient algo‐
391 rithm for managing the available inline inode space
392 between attribute and extent data.
393 The previous version 1, which has fixed regions for
395 attribute and extent data, is kept for backwards
396 compatibility with kernels older than version
397 2.6.16.
398 projid32bit[=value]
400 This is used to enable 32bit quota project identi‐
401 fiers. The value is either 0 or 1, with 1 signifying
402 that 32bit projid are to be enabled. If the value
403 is omitted, 1 is assumed. (This default changed in
404 release version 3.2.0.)
405 sparse[=value]
407 Enable sparse inode chunk allocation. The value is
408 either 0 or 1, with 1 signifying that sparse alloca‐
409 tion is enabled. If the value is omitted, 1 is
410 assumed. Sparse inode allocation is disabled by
411 default. This feature is only available for filesys‐
412 tems formatted with -m crc=1.
413 When enabled, sparse inode allocation allows the
415 filesystem to allocate smaller than the standard
416 64-inode chunk when free space is severely limited.
417 This feature is useful for filesystems that might
418 fragment free space over time such that no free
419 extents are large enough to accommodate a chunk of
420 64 inodes. Without this feature enabled, inode allo‐
421 cations can fail with out of space errors under
422 severe fragmented free space conditions.
423 -l log_section_options
425 These options specify the location, size, and other parameters
426 of the log section of the filesystem. The valid log_sec‐
427 tion_options are:
428 agnum=value
430 If the log is internal, allocate it in this AG.
431 internal[=value]
433 This is used to specify that the log section is a
434 piece of the data section instead of being another
435 device or logical volume. The value is either 0 or
436 1, with 1 signifying that the log is internal. If
437 the value is omitted, 1 is assumed.
438 logdev=device
440 This is used to specify that the log section should
441 reside on the device separate from the data section.
442 The internal=1 and logdev options are mutually
443 exclusive.
444 size=value
446 This is used to specify the size of the log section.
447 If the log is contained within the data section and
449 size isn't specified, mkfs.xfs will try to select a
450 suitable log size depending on the size of the
451 filesystem. The actual logsize depends on the
452 filesystem block size and the directory block size.
453 Otherwise, the size suboption is only needed if the
455 log section of the filesystem should occupy less
456 space than the size of the special file. The value
457 is specified in bytes or blocks, with a b suffix
458 meaning multiplication by the filesystem block size,
459 as described above. The overriding minimum value for
460 size is 512 blocks. With some combinations of
461 filesystem block size, inode size, and directory
462 block size, the minimum log size is larger than 512
463 blocks.
464 version=value
466 This specifies the version of the log. The current
467 default is 2, which allows for larger log buffer
468 sizes, as well as supporting stripe-aligned log
469 writes (see the sunit and su options, below).
470 The previous version 1, which is limited to 32k log
472 buffers and does not support stripe-aligned writes,
473 is kept for backwards compatibility with very old
474 2.4 kernels.
475 sunit=value
477 This specifies the alignment to be used for log
478 writes. The value has to be specified in 512-byte
479 block units. Use the su suboption to specify the log
480 stripe unit size in bytes. Log writes will be
481 aligned on this boundary, and rounded up to this
482 boundary. This gives major improvements in perfor‐
483 mance on some configurations such as software RAID5
484 when the sunit is specified as the filesystem block
485 size. The equivalent byte value must be a multiple
486 of the filesystem block size. Version 2 logs are
487 automatically selected if the log sunit suboption is
488 specified.
489 The su suboption is an alternative to using sunit.
491 su=value
493 This is used to specify the log stripe. The value
494 has to be specified in bytes, (usually using the s
495 or b suffixes). This value must be a multiple of the
496 filesystem block size. Version 2 logs are automati‐
497 cally selected if the log su suboption is specified.
498 lazy-count=value
500 This changes the method of logging various persis‐
501 tent counters in the superblock. Under metadata
502 intensive workloads, these counters are updated and
503 logged frequently enough that the superblock updates
504 become a serialization point in the filesystem. The
505 value can be either 0 or 1.
506 With lazy-count=1, the superblock is not modified or
508 logged on every change of the persistent counters.
509 Instead, enough information is kept in other parts
510 of the filesystem to be able to maintain the persis‐
511 tent counter values without needed to keep them in
512 the superblock. This gives significant improvements
513 in performance on some configurations. The default
514 value is 1 (on) so you must specify lazy-count=0 if
515 you want to disable this feature for older kernels
516 which don't support it.
517 -n naming_options
519 These options specify the version and size parameters for the
520 naming (directory) area of the filesystem. The valid nam‐
521 ing_options are:
522 size=value
524 The directory block size is specified with a value
525 in bytes. The block size must be a power of 2 and
526 cannot be less than the filesystem block size. The
527 default size value for version 2 directories is 4096
528 bytes (4 KiB), unless the filesystem block size is
529 larger than 4096, in which case the default value is
530 the filesystem block size. For version 1 directo‐
531 ries the block size is the same as the filesystem
532 block size.
533 version=value
535 The naming (directory) version value can be either 2
536 or 'ci', defaulting to 2 if unspecified. With ver‐
537 sion 2 directories, the directory block size can be
538 any power of 2 size from the filesystem block size
539 up to 65536.
540 The version=ci option enables ASCII only case-insen‐
542 sitive filename lookup and version 2 directories.
543 Filenames are case-preserving, that is, the names
544 are stored in directories using the case they were
545 created with.
546 Note: Version 1 directories are not supported.
548 ftype=value
550 This feature allows the inode type to be stored in
551 the directory structure so that the readdir(3) and
552 getdents(2) do not need to look up the inode to
553 determine the inode type.
554 The value is either 0 or 1, with 1 signifying that
556 filetype information will be stored in the directory
557 structure. The default value is 1.
558 When CRCs are enabled (the default), the ftype func‐
560 tionality is always enabled, and cannot be turned
561 off.
562 -p protofile
564 If the optional -p protofile argument is given, mkfs.xfs uses
565 protofile as a prototype file and takes its directions from that
566 file. The blocks and inodes specifiers in the protofile are
567 provided for backwards compatibility, but are otherwise unused.
568 The syntax of the protofile is defined by a number of tokens
569 separated by spaces or newlines. Note that the line numbers are
570 not part of the syntax but are meant to help you in the follow‐
571 ing discussion of the file contents.
572 1 /stand/diskboot
574 2 4872 110
575 3 d--777 3 1
576 4 usr d--777 3 1
577 5 sh ---755 3 1 /bin/sh
578 6 ken d--755 6 1
579 7 $
580 8 b0 b--644 3 1 0 0
581 9 c0 c--644 3 1 0 0
582 10 fifo p--644 3 1
583 11 slink l--644 3 1 /a/symbolic/link
584 12 : This is a comment line
585 13 $
586 14 $
587 Line 1 is a dummy string. (It was formerly the bootfilename.)
589 It is present for backward compatibility; boot blocks are not
590 used on SGI systems.
591 Note that some string of characters must be present as the first
593 line of the proto file to cause it to be parsed correctly; the
594 value of this string is immaterial since it is ignored.
595 Line 2 contains two numeric values (formerly the numbers of
597 blocks and inodes). These are also merely for backward compati‐
598 bility: two numeric values must appear at this point for the
599 proto file to be correctly parsed, but their values are immate‐
600 rial since they are ignored.
601 The lines 3 through 11 specify the files and directories you
603 want to include in this filesystem. Line 3 defines the root
604 directory. Other directories and files that you want in the
605 filesystem are indicated by lines 4 through 6 and lines 8
606 through 10. Line 11 contains symbolic link syntax.
607 Notice the dollar sign ($) syntax on line 7. This syntax directs
609 the mkfs.xfs command to terminate the branch of the filesystem
610 it is currently on and then continue from the directory speci‐
611 fied by the next line, in this case line 8. It must be the last
612 character on a line. The colon on line 12 introduces a comment;
613 all characters up until the following newline are ignored. Note
614 that this means you cannot have a file in a prototype file whose
615 name contains a colon. The $ on lines 13 and 14 end the
616 process, since no additional specifications follow.
617 File specifications provide the following:
619 * file mode
621 * user ID
622 * group ID
623 * the file's beginning contents
624 A 6-character string defines the mode for a file. The first
626 character of this string defines the file type. The character
627 range for this first character is -bcdpl. A file may be a regu‐
628 lar file, a block special file, a character special file, direc‐
629 tory files, named pipes (first-in, first out files), and sym‐
630 bolic links. The second character of the mode string is used to
631 specify setuserID mode, in which case it is u. If setuserID
632 mode is not specified, the second character is -. The third
633 character of the mode string is used to specify the setgroupID
634 mode, in which case it is g. If setgroupID mode is not speci‐
635 fied, the third character is -. The remaining characters of the
636 mode string are a three digit octal number. This octal number
637 defines the owner, group, and other read, write, and execute
638 permissions for the file, respectively. For more information on
639 file permissions, see the chmod(1) command.
640 Following the mode character string are two decimal number
642 tokens that specify the user and group IDs of the file's owner.
643 In a regular file, the next token specifies the pathname from
645 which the contents and size of the file are copied. In a block
646 or character special file, the next token are two decimal num‐
647 bers that specify the major and minor device numbers. When a
648 file is a symbolic link, the next token specifies the contents
649 of the link.
650 When the file is a directory, the mkfs.xfs command creates the
652 entries dot (.) and dot-dot (..) and then reads the list of
653 names and file specifications in a recursive manner for all of
654 the entries in the directory. A scan of the protofile is always
655 terminated with the dollar ( $ ) token.
656 -q Quiet option. Normally mkfs.xfs prints the parameters of the
658 filesystem to be constructed; the -q flag suppresses this.
659 -r realtime_section_options
661 These options specify the location, size, and other parameters
662 of the real-time section of the filesystem. The valid real‐
663 time_section_options are:
664 rtdev=device
666 This is used to specify the device which should con‐
667 tain the real-time section of the filesystem. The
668 suboption value is the name of a block device.
669 extsize=value
671 This is used to specify the size of the blocks in
672 the real-time section of the filesystem. This value
673 must be a multiple of the filesystem block size. The
674 minimum allowed size is the filesystem block size or
675 4 KiB (whichever is larger); the default size is the
676 stripe width for striped volumes or 64 KiB for non-
677 striped volumes; the maximum allowed size is 1 GiB.
678 The real-time extent size should be carefully chosen
679 to match the parameters of the physical media used.
680 size=value
682 This is used to specify the size of the real-time
683 section. This suboption is only needed if the real-
684 time section of the filesystem should occupy less
685 space than the size of the partition or logical vol‐
686 ume containing the section.
687 noalign
689 This option disables stripe size detection, enforc‐
690 ing a realtime device with no stripe geometry.
691 -s sector_size_options
693 This option specifies the fundamental sector size of the
694 filesystem. The valid sector_size_option is:
695 size=value
697 The sector size is specified with a value in bytes.
698 The default sector_size is 512 bytes. The minimum
699 value for sector size is 512; the maximum is 32768
700 (32 KiB). The sector_size must be a power of 2 size
701 and cannot be made larger than the filesystem block
702 size.
703 -L label
705 Set the filesystem label. XFS filesystem labels can be at most
706 12 characters long; if label is longer than 12 characters,
707 mkfs.xfs will not proceed with creating the filesystem. Refer
708 to the mount(8) and xfs_admin(8) manual entries for additional
709 information.
710 -N Causes the file system parameters to be printed out without
712 really creating the file system.
713 -K Do not attempt to discard blocks at mkfs time.
715 -V Prints the version number and exits.
717
719 xfs(5), mkfs(8), mount(8), xfs_info(8), xfs_admin(8).
720
722 With a prototype file, it is not possible to specify hard links.
723 mkfs.xfs(8)