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 first needs to be added to the command
58 line. Failure to specify the size of the units will result in illegal
59 value errors when parameters are quantified in those units.
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 To specify any options on the command line in units
76 of filesystem blocks, this option must be specified
77 first so that the filesystem block size is applied
78 consistently to all options.
79 Although mkfs.xfs will accept any of these values
81 and create a valid filesystem, XFS on Linux can only
82 mount filesystems with pagesize or smaller blocks.
83 -m global_metadata_options
85 These options specify metadata format options that either apply
86 to the entire filesystem or aren't easily characterised by a
87 specific functionality group. The valid global_metadata_options
88 are:
89 crc=value
91 This is used to create a filesystem which maintains
92 and checks CRC information in all metadata objects
93 on disk. The value is either 0 to disable the fea‐
94 ture, or 1 to enable the use of CRCs.
95 CRCs enable enhanced error detection due to hardware
97 issues, whilst the format changes also improves
98 crash recovery algorithms and the ability of various
99 tools to validate and repair metadata corruptions
100 when they are found. The CRC algorithm used is
101 CRC32c, so the overhead is dependent on CPU archi‐
102 tecture as some CPUs have hardware acceleration of
103 this algorithm. Typically the overhead of calculat‐
104 ing and checking the CRCs is not noticeable in nor‐
105 mal operation.
106 By default, mkfs.xfs will enable metadata CRCs.
108 finobt=value
110 This option enables the use of a separate free inode
111 btree index in each allocation group. The value is
112 either 0 to disable the feature, or 1 to create a
113 free inode btree in each allocation group.
114 The free inode btree mirrors the existing allocated
116 inode btree index which indexes both used and free
117 inodes. The free inode btree does not index used
118 inodes, allowing faster, more consistent inode allo‐
119 cation performance as filesystems age.
120 By default, mkfs.xfs will create free inode btrees
122 for filesystems created with the (default) -m crc=1
123 option set. When the option -m crc=0 is used, the
124 free inode btree feature is not supported and is
125 disabled.
126 uuid=value
128 Use the given value as the filesystem UUID for the
129 newly created filesystem. The default is to gener‐
130 ate a random UUID.
131 rmapbt=value
133 This option enables the creation of a reverse-map‐
134 ping btree index in each allocation group. The
135 value is either 0 to disable the feature, or 1 to
136 create the btree.
137 The reverse mapping btree maps filesystem blocks to
139 the owner of the filesystem block. Most of the map‐
140 pings will be to an inode number and an offset,
141 though there will also be mappings to filesystem
142 metadata. This secondary metadata can be used to
143 validate the primary metadata or to pinpoint exactly
144 which data has been lost when a disk error occurs.
145 By default, mkfs.xfs will not create reverse mapping
147 btrees. This feature is only available for filesys‐
148 tems created with the (default) -m crc=1 option set.
149 When the option -m crc=0 is used, the reverse map‐
150 ping btree feature is not supported and is disabled.
151 reflink=value
153 This option enables the use of a separate reference
154 count btree index in each allocation group. The
155 value is either 0 to disable the feature, or 1 to
156 create a reference count btree in each allocation
157 group.
158 The reference count btree enables the sharing of
160 physical extents between the data forks of different
161 files, which is commonly known as "reflink". Unlike
162 traditional Unix filesystems which assume that every
163 inode and logical block pair map to a unique physi‐
164 cal block, a reflink-capable XFS filesystem removes
165 the uniqueness requirement, allowing up to four bil‐
166 lion arbitrary inode/logical block pairs to map to a
167 physical block. If a program tries to write to a
168 multiply-referenced block in a file, the write will
169 be redirected to a new block, and that file's logi‐
170 cal-to-physical mapping will be changed to the new
171 block ("copy on write"). This feature enables the
172 creation of per-file snapshots and deduplication.
173 It is only available for the data forks of regular
174 files.
175 By default in Red Hat Enterprise Linux 8, mkfs.xfs
177 will create reference count btrees and therefore
178 will enable the reflink feature. This feature is
179 only available for filesystems created with the
180 (default) -m crc=1 option set. When the option -m
181 crc=0 is used, the reference count btree feature is
182 not supported and reflink is disabled.
183 Note: the filesystem DAX mount option ( -o dax ) is
185 incompatible with reflink-enabled XFS filesystems.
186 To use filesystem DAX with XFS, specify the -m
187 reflink=0 option to mkfs.xfs to disable the reflink
188 feature.
189 -d data_section_options
191 These options specify the location, size, and other parameters
192 of the data section of the filesystem. The valid data_sec‐
193 tion_options are:
194 agcount=value
196 This is used to specify the number of allocation
197 groups. The data section of the filesystem is
198 divided into allocation groups to improve the per‐
199 formance of XFS. More allocation groups imply that
200 more parallelism can be achieved when allocating
201 blocks and inodes. The minimum allocation group size
202 is 16 MiB; the maximum size is just under 1 TiB.
203 The data section of the filesystem is divided into
204 value allocation groups (default value is scaled
205 automatically based on the underlying device size).
206 agsize=value
208 This is an alternative to using the agcount subop‐
209 tion. The value is the desired size of the alloca‐
210 tion group expressed in bytes (usually using the m
211 or g suffixes). This value must be a multiple of
212 the filesystem block size, and must be at least
213 16MiB, and no more than 1TiB, and may be automati‐
214 cally adjusted to properly align with the stripe
215 geometry. The agcount and agsize suboptions are
216 mutually exclusive.
217 cowextsize=value
219 Set the copy-on-write extent size hint on all inodes
220 created by mkfs.xfs. The value must be provided in
221 units of filesystem blocks. If the value is zero,
222 the default value (currently 32 blocks) will be
223 used. Directories will pass on this hint to newly
224 created children.
225 name=value
227 This can be used to specify the name of the special
228 file containing the filesystem. In this case, the
229 log section must be specified as internal (with a
230 size, see the -l option below) and there can be no
231 real-time section.
232 file[=value]
234 This is used to specify that the file given by the
235 name suboption is a regular file. The value is
236 either 0 or 1, with 1 signifying that the file is
237 regular. This suboption is used only to make a
238 filesystem image. If the value is omitted then 1 is
239 assumed.
240 size=value
242 This is used to specify the size of the data sec‐
243 tion. This suboption is required if -d file[=1] is
244 given. Otherwise, it is only needed if the filesys‐
245 tem should occupy less space than the size of the
246 special file.
247 sunit=value
249 This is used to specify the stripe unit for a RAID
250 device or a logical volume. The value has to be
251 specified in 512-byte block units. Use the su subop‐
252 tion to specify the stripe unit size in bytes. This
253 suboption ensures that data allocations will be
254 stripe unit aligned when the current end of file is
255 being extended and the file size is larger than
256 512KiB. Also inode allocations and the internal log
257 will be stripe unit aligned.
258 su=value
260 This is an alternative to using sunit. The su sub‐
261 option is used to specify the stripe unit for a RAID
262 device or a striped logical volume. The value has to
263 be specified in bytes, (usually using the m or g
264 suffixes). This value must be a multiple of the
265 filesystem block size.
266 swidth=value
268 This is used to specify the stripe width for a RAID
269 device or a striped logical volume. The value has to
270 be specified in 512-byte block units. Use the sw
271 suboption to specify the stripe width size in bytes.
272 This suboption is required if -d sunit has been
273 specified and it has to be a multiple of the -d
274 sunit suboption.
275 sw=value
277 suboption is an alternative to using swidth. The sw
278 suboption is used to specify the stripe width for a
279 RAID device or striped logical volume. The value is
280 expressed as a multiplier of the stripe unit, usu‐
281 ally the same as the number of stripe members in the
282 logical volume configuration, or data disks in a
283 RAID device.
284 When a filesystem is created on a logical volume
286 device, mkfs.xfs will automatically query the logi‐
287 cal volume for appropriate sunit and swidth values.
288 noalign
290 This option disables automatic geometry detection
291 and creates the filesystem without stripe geometry
292 alignment even if the underlying storage device pro‐
293 vides this information.
294 rtinherit=value
296 If set, all inodes created by mkfs.xfs will be cre‐
297 ated with the realtime flag set. Directories will
298 pass on this flag to newly created children.
299 projinherit=value
301 All inodes created by mkfs.xfs will be assigned this
302 project quota id. Directories will pass on the
303 project id to newly created children.
304 extszinherit=value
306 All inodes created by mkfs.xfs will have this extent
307 size hint applied. The value must be provided in
308 units of filesystem blocks. Directories will pass
309 on this hint to newly created children.
310 -f Force overwrite when an existing filesystem is detected on the
312 device. By default, mkfs.xfs will not write to the device if it
313 suspects that there is a filesystem or partition table on the
314 device already.
315 -i inode_options
317 This option specifies the inode size of the filesystem, and
318 other inode allocation parameters. The XFS inode contains a
319 fixed-size part and a variable-size part. The variable-size
320 part, whose size is affected by this option, can contain: direc‐
321 tory data, for small directories; attribute data, for small
322 attribute sets; symbolic link data, for small symbolic links;
323 the extent list for the file, for files with a small number of
324 extents; and the root of a tree describing the location of
325 extents for the file, for files with a large number of extents.
326 The valid inode_options are:
328 size=value | perblock=value
330 The inode size is specified either as a value in
331 bytes with size= or as the number fitting in a
332 filesystem block with perblock=. The minimum (and
333 default) value is 256 bytes without crc, 512 bytes
334 with crc enabled. The maximum value is 2048 (2 KiB)
335 subject to the restriction that the inode size can‐
336 not exceed one half of the filesystem block size.
337 XFS uses 64-bit inode numbers internally; however,
339 the number of significant bits in an inode number is
340 affected by filesystem geometry. In practice,
341 filesystem size and inode size are the predominant
342 factors. The Linux kernel (on 32 bit hardware plat‐
343 forms) and most applications cannot currently handle
344 inode numbers greater than 32 significant bits, so
345 if no inode size is given on the command line,
346 mkfs.xfs will attempt to choose a size such that
347 inode numbers will be < 32 bits. If an inode size
348 is specified, or if a filesystem is sufficiently
349 large, mkfs.xfs will warn if this will create inode
350 numbers > 32 significant bits.
351 maxpct=value
353 This specifies the maximum percentage of space in
354 the filesystem that can be allocated to inodes. The
355 default value is 25% for filesystems under 1TB, 5%
356 for filesystems under 50TB and 1% for filesystems
357 over 50TB.
358 In the default inode allocation mode, inode blocks
360 are chosen such that inode numbers will not exceed
361 32 bits, which restricts the inode blocks to the
362 lower portion of the filesystem. The data block
363 allocator will avoid these low blocks to accommodate
364 the specified maxpct, so a high value may result in
365 a filesystem with nothing but inodes in a signifi‐
366 cant portion of the lower blocks of the filesystem.
367 (This restriction is not present when the filesystem
368 is mounted with the inode64 option on 64-bit plat‐
369 forms).
370 Setting the value to 0 means that essentially all of
372 the filesystem can become inode blocks, subject to
373 inode32 restrictions.
374 This value can be modified with xfs_growfs(8).
376 align[=value]
378 This is used to specify that inode allocation is or
379 is not aligned. The value is either 0 or 1, with 1
380 signifying that inodes are allocated aligned. If
381 the value is omitted, 1 is assumed. The default is
382 that inodes are aligned. Aligned inode access is
383 normally more efficient than unaligned access;
384 alignment must be established at the time the
385 filesystem is created, since inodes are allocated at
386 that time. This option can be used to turn off
387 inode alignment when the filesystem needs to be
388 mountable by a version of IRIX that does not have
389 the inode alignment feature (any release of IRIX
390 before 6.2, and IRIX 6.2 without XFS patches).
391 attr=value
393 This is used to specify the version of extended
394 attribute inline allocation policy to be used. By
395 default, this is 2, which uses an efficient algo‐
396 rithm for managing the available inline inode space
397 between attribute and extent data.
398 The previous version 1, which has fixed regions for
400 attribute and extent data, is kept for backwards
401 compatibility with kernels older than version
402 2.6.16.
403 projid32bit[=value]
405 This is used to enable 32bit quota project identi‐
406 fiers. The value is either 0 or 1, with 1 signifying
407 that 32bit projid are to be enabled. If the value
408 is omitted, 1 is assumed. (This default changed in
409 release version 3.2.0.)
410 sparse[=value]
412 Enable sparse inode chunk allocation. The value is
413 either 0 or 1, with 1 signifying that sparse alloca‐
414 tion is enabled. If the value is omitted, 1 is
415 assumed. Sparse inode allocation is disabled by
416 default. This feature is only available for filesys‐
417 tems formatted with -m crc=1.
418 When enabled, sparse inode allocation allows the
420 filesystem to allocate smaller than the standard
421 64-inode chunk when free space is severely limited.
422 This feature is useful for filesystems that might
423 fragment free space over time such that no free
424 extents are large enough to accommodate a chunk of
425 64 inodes. Without this feature enabled, inode allo‐
426 cations can fail with out of space errors under
427 severe fragmented free space conditions.
428 -l log_section_options
430 These options specify the location, size, and other parameters
431 of the log section of the filesystem. The valid log_sec‐
432 tion_options are:
433 agnum=value
435 If the log is internal, allocate it in this AG.
436 internal[=value]
438 This is used to specify that the log section is a
439 piece of the data section instead of being another
440 device or logical volume. The value is either 0 or
441 1, with 1 signifying that the log is internal. If
442 the value is omitted, 1 is assumed.
443 logdev=device
445 This is used to specify that the log section should
446 reside on the device separate from the data section.
447 The internal=1 and logdev options are mutually
448 exclusive.
449 size=value
451 This is used to specify the size of the log section.
452 If the log is contained within the data section and
454 size isn't specified, mkfs.xfs will try to select a
455 suitable log size depending on the size of the
456 filesystem. The actual logsize depends on the
457 filesystem block size and the directory block size.
458 Otherwise, the size suboption is only needed if the
460 log section of the filesystem should occupy less
461 space than the size of the special file. The value
462 is specified in bytes or blocks, with a b suffix
463 meaning multiplication by the filesystem block size,
464 as described above. The overriding minimum value for
465 size is 512 blocks. With some combinations of
466 filesystem block size, inode size, and directory
467 block size, the minimum log size is larger than 512
468 blocks.
469 version=value
471 This specifies the version of the log. The current
472 default is 2, which allows for larger log buffer
473 sizes, as well as supporting stripe-aligned log
474 writes (see the sunit and su options, below).
475 The previous version 1, which is limited to 32k log
477 buffers and does not support stripe-aligned writes,
478 is kept for backwards compatibility with very old
479 2.4 kernels.
480 sunit=value
482 This specifies the alignment to be used for log
483 writes. The value has to be specified in 512-byte
484 block units. Use the su suboption to specify the log
485 stripe unit size in bytes. Log writes will be
486 aligned on this boundary, and rounded up to this
487 boundary. This gives major improvements in perfor‐
488 mance on some configurations such as software RAID5
489 when the sunit is specified as the filesystem block
490 size. The equivalent byte value must be a multiple
491 of the filesystem block size. Version 2 logs are
492 automatically selected if the log sunit suboption is
493 specified.
494 The su suboption is an alternative to using sunit.
496 su=value
498 This is used to specify the log stripe. The value
499 has to be specified in bytes, (usually using the s
500 or b suffixes). This value must be a multiple of the
501 filesystem block size. Version 2 logs are automati‐
502 cally selected if the log su suboption is specified.
503 lazy-count=value
505 This changes the method of logging various persis‐
506 tent counters in the superblock. Under metadata
507 intensive workloads, these counters are updated and
508 logged frequently enough that the superblock updates
509 become a serialization point in the filesystem. The
510 value can be either 0 or 1.
511 With lazy-count=1, the superblock is not modified or
513 logged on every change of the persistent counters.
514 Instead, enough information is kept in other parts
515 of the filesystem to be able to maintain the persis‐
516 tent counter values without needed to keep them in
517 the superblock. This gives significant improvements
518 in performance on some configurations. The default
519 value is 1 (on) so you must specify lazy-count=0 if
520 you want to disable this feature for older kernels
521 which don't support it.
522 -n naming_options
524 These options specify the version and size parameters for the
525 naming (directory) area of the filesystem. The valid nam‐
526 ing_options are:
527 size=value
529 The directory block size is specified with a value
530 in bytes. The block size must be a power of 2 and
531 cannot be less than the filesystem block size. The
532 default size value for version 2 directories is 4096
533 bytes (4 KiB), unless the filesystem block size is
534 larger than 4096, in which case the default value is
535 the filesystem block size. For version 1 directo‐
536 ries the block size is the same as the filesystem
537 block size.
538 version=value
540 The naming (directory) version value can be either 2
541 or 'ci', defaulting to 2 if unspecified. With ver‐
542 sion 2 directories, the directory block size can be
543 any power of 2 size from the filesystem block size
544 up to 65536.
545 The version=ci option enables ASCII only case-insen‐
547 sitive filename lookup and version 2 directories.
548 Filenames are case-preserving, that is, the names
549 are stored in directories using the case they were
550 created with.
551 Note: Version 1 directories are not supported.
553 ftype=value
555 This feature allows the inode type to be stored in
556 the directory structure so that the readdir(3) and
557 getdents(2) do not need to look up the inode to
558 determine the inode type.
559 The value is either 0 or 1, with 1 signifying that
561 filetype information will be stored in the directory
562 structure. The default value is 1.
563 When CRCs are enabled (the default), the ftype func‐
565 tionality is always enabled, and cannot be turned
566 off.
567 -p protofile
569 If the optional -p protofile argument is given, mkfs.xfs uses
570 protofile as a prototype file and takes its directions from that
571 file. The blocks and inodes specifiers in the protofile are
572 provided for backwards compatibility, but are otherwise unused.
573 The syntax of the protofile is defined by a number of tokens
574 separated by spaces or newlines. Note that the line numbers are
575 not part of the syntax but are meant to help you in the follow‐
576 ing discussion of the file contents.
577 1 /stand/diskboot
579 2 4872 110
580 3 d--777 3 1
581 4 usr d--777 3 1
582 5 sh ---755 3 1 /bin/sh
583 6 ken d--755 6 1
584 7 $
585 8 b0 b--644 3 1 0 0
586 9 c0 c--644 3 1 0 0
587 10 fifo p--644 3 1
588 11 slink l--644 3 1 /a/symbolic/link
589 12 : This is a comment line
590 13 $
591 14 $
592 Line 1 is a dummy string. (It was formerly the bootfilename.)
594 It is present for backward compatibility; boot blocks are not
595 used on SGI systems.
596 Note that some string of characters must be present as the first
598 line of the proto file to cause it to be parsed correctly; the
599 value of this string is immaterial since it is ignored.
600 Line 2 contains two numeric values (formerly the numbers of
602 blocks and inodes). These are also merely for backward compati‐
603 bility: two numeric values must appear at this point for the
604 proto file to be correctly parsed, but their values are immate‐
605 rial since they are ignored.
606 The lines 3 through 11 specify the files and directories you
608 want to include in this filesystem. Line 3 defines the root
609 directory. Other directories and files that you want in the
610 filesystem are indicated by lines 4 through 6 and lines 8
611 through 10. Line 11 contains symbolic link syntax.
612 Notice the dollar sign ($) syntax on line 7. This syntax directs
614 the mkfs.xfs command to terminate the branch of the filesystem
615 it is currently on and then continue from the directory speci‐
616 fied by the next line, in this case line 8. It must be the last
617 character on a line. The colon on line 12 introduces a comment;
618 all characters up until the following newline are ignored. Note
619 that this means you cannot have a file in a prototype file whose
620 name contains a colon. The $ on lines 13 and 14 end the
621 process, since no additional specifications follow.
622 File specifications provide the following:
624 * file mode
626 * user ID
627 * group ID
628 * the file's beginning contents
629 A 6-character string defines the mode for a file. The first
631 character of this string defines the file type. The character
632 range for this first character is -bcdpl. A file may be a regu‐
633 lar file, a block special file, a character special file, direc‐
634 tory files, named pipes (first-in, first out files), and sym‐
635 bolic links. The second character of the mode string is used to
636 specify setuserID mode, in which case it is u. If setuserID
637 mode is not specified, the second character is -. The third
638 character of the mode string is used to specify the setgroupID
639 mode, in which case it is g. If setgroupID mode is not speci‐
640 fied, the third character is -. The remaining characters of the
641 mode string are a three digit octal number. This octal number
642 defines the owner, group, and other read, write, and execute
643 permissions for the file, respectively. For more information on
644 file permissions, see the chmod(1) command.
645 Following the mode character string are two decimal number
647 tokens that specify the user and group IDs of the file's owner.
648 In a regular file, the next token specifies the pathname from
650 which the contents and size of the file are copied. In a block
651 or character special file, the next token are two decimal num‐
652 bers that specify the major and minor device numbers. When a
653 file is a symbolic link, the next token specifies the contents
654 of the link.
655 When the file is a directory, the mkfs.xfs command creates the
657 entries dot (.) and dot-dot (..) and then reads the list of
658 names and file specifications in a recursive manner for all of
659 the entries in the directory. A scan of the protofile is always
660 terminated with the dollar ( $ ) token.
661 -q Quiet option. Normally mkfs.xfs prints the parameters of the
663 filesystem to be constructed; the -q flag suppresses this.
664 -r realtime_section_options
666 These options specify the location, size, and other parameters
667 of the real-time section of the filesystem. The valid real‐
668 time_section_options are:
669 rtdev=device
671 This is used to specify the device which should con‐
672 tain the real-time section of the filesystem. The
673 suboption value is the name of a block device.
674 extsize=value
676 This is used to specify the size of the blocks in
677 the real-time section of the filesystem. This value
678 must be a multiple of the filesystem block size. The
679 minimum allowed size is the filesystem block size or
680 4 KiB (whichever is larger); the default size is the
681 stripe width for striped volumes or 64 KiB for non-
682 striped volumes; the maximum allowed size is 1 GiB.
683 The real-time extent size should be carefully chosen
684 to match the parameters of the physical media used.
685 size=value
687 This is used to specify the size of the real-time
688 section. This suboption is only needed if the real-
689 time section of the filesystem should occupy less
690 space than the size of the partition or logical vol‐
691 ume containing the section.
692 noalign
694 This option disables stripe size detection, enforc‐
695 ing a realtime device with no stripe geometry.
696 -s sector_size_options
698 This option specifies the fundamental sector size of the
699 filesystem. The valid sector_size_option is:
700 size=value
702 The sector size is specified with a value in bytes.
703 The default sector_size is 512 bytes. The minimum
704 value for sector size is 512; the maximum is 32768
705 (32 KiB). The sector_size must be a power of 2 size
706 and cannot be made larger than the filesystem block
707 size.
708 To specify any options on the command line in units
710 of sectors, this option must be specified first so
711 that the sector size is applied consistently to all
712 options.
713 -L label
715 Set the filesystem label. XFS filesystem labels can be at most
716 12 characters long; if label is longer than 12 characters,
717 mkfs.xfs will not proceed with creating the filesystem. Refer
718 to the mount(8) and xfs_admin(8) manual entries for additional
719 information.
720 -N Causes the file system parameters to be printed out without
722 really creating the file system.
723 -K Do not attempt to discard blocks at mkfs time.
725 -V Prints the version number and exits.
727
729 xfs(5), mkfs(8), mount(8), xfs_info(8), xfs_admin(8).
730
732 With a prototype file, it is not possible to specify hard links.
733 mkfs.xfs(8)