.B mke2fs \-C
option.
.IP
-.B Warning:
-The bigalloc feature is still under development, and may not be fully
+.B WARNING:
+The \fBbigalloc\fR feature is still under development, and may not be fully
supported with your kernel or may have various bugs. Please see the web
page http://ext4.wiki.kernel.org/index.php/Bigalloc for details.
May clash with delayed allocation (see
file system which uses it.
.IP
The external journal device can be used by a file system by specifying
-the
-.B \-J
-.BR device= <external-device>
-option to
-.BR mke2fs (8)
-or
-.BR tune2fs 8) .
+the \fB\-J device=\fR<\fIexternal-device\fR> option to
+\fBmke2fs\fR(8) or \fBtune2fs\fR(8).
.TP
.B large_dir
.br
This file system feature indicates that space has been reserved so that
the block group descriptor table can be extended while resizing a mounted
file system. The online resize operation
-is carried out by the kernel, triggered by
-.BR resize2fs (8).
-By default
-.B mke2fs
-will attempt to reserve enough space so that the
+is carried out by the kernel, triggered by \fBresize2fs\fR(8). By default
+\fBmke2fs\fR(8) will attempt to reserve enough space so that the
file system may grow to 1024 times its initial size. This can be changed
using the
.B resize
the backup superblock(s) and blockgroup descriptor(s) are stored in the
superblock, but typically, one will be located at the beginning of block
group #1, and one in the last block group in the file system. This
-feature is essentially a more extreme version of sparse_super and is
+feature is essentially a more extreme version of \fBsparse_super\fR and is
designed to allow a much larger percentage of the disk to have
contiguous blocks available for data files.
.TP
.BR mount (8)
for details.
.SH "Mount options for ext2"
-The `ext2' file system is the standard Linux file system.
+The ext2 file system is the standard Linux file system.
Since Linux 2.5.46, for most mount options the default
is determined by the file system superblock. Set them with
.BR tune2fs (8).
.TP
-.BR acl | noacl
-Support POSIX Access Control Lists (or not). See the
-.BR acl (5)
-manual page.
+.BR acl " | " noacl
+Support POSIX Access Control Lists (or not). See the \fBacl\fR(5) manual page.
.TP
-.BR bsddf | minixdf
-Set the behavior for the
-.I statfs
-system call. The
-.B minixdf
-behavior is to return in the
-.I f_blocks
-field the total number of blocks of the file system, while the
-.B bsddf
+.BR bsddf " | " minixdf
+Set the behavior for the \fIstatfs\fR system call. The \fBminixdf\fR
+behavior is to return in the \fIf_blocks\fR
+field the total number of blocks of the file system, while the \fBbsddf\fR
behavior (which is the default) is to subtract the overhead blocks
used by the ext2 file system and not available for file storage. Thus
.sp 1
to the options given in
.IR /etc/fstab .)
.TP
-.BR check=none " or " nocheck
-No checking is done at mount time. This is the default. This is fast.
-It is wise to invoke
-.BR e2fsck (8)
-every now and then, e.g.\& at boot time. The non-default behavior is unsupported
-(check=normal and check=strict options have been removed). Note that these mount options
+.BR check=none " | " nocheck
+No checking is done at mount time. This is the default. This is fast.
+It is wise to invoke \fBe2fsck\fR(8) every now and then, e.g.\& at boot time.
+The non-default behavior is unsupported (\fBcheck=normal\fR and
+\fBcheck=strict\fR options have been removed). Note that these mount options
don't have to be supported if ext4 kernel driver is used for ext2 and ext3 file systems.
.TP
.B debug
changed using
.BR tune2fs (8).
.TP
-.BR grpid | bsdgroups " and " nogrpid | sysvgroups
+.BR grpid " | " bsdgroups " and " nogrpid " | " sysvgroups
These options define what group id a newly created file gets.
When
.B grpid
from the parent directory, and also gets the setgid bit set
if it is a directory itself.
.TP
-.BR grpquota | noquota | quota | usrquota
-The usrquota (same as quota) mount option enables user quota support on the
-file system. grpquota enables group quotas support. You need the quota utilities
-to actually enable and manage the quota system.
+.BR grpquota " | " usrquota " | " quota " | " noquota
+The \fBusrquota\fR (same as \fBquota\fR) mount option enables user quota
+support on the file system. \fBgrpquota\fR enables group quotas support.
+You need the \fBquota\fR(1) utilities to actually enable and manage the quota
+system.
.TP
.B nouid32
Disables 32-bit UIDs and GIDs. This is for interoperability with older
kernels which only store and expect 16-bit values.
.TP
-.BR oldalloc " or " orlov
+.BR oldalloc " | " orlov
Use old allocator or Orlov allocator for new inodes. Orlov is default.
.TP
\fBresgid=\fP\,\fIn\fP and \fBresuid=\fP\,\fIn\fP
such as
.BR sparse_super .
.IP
-Additional backup superblocks can be determined by using the
-.B mke2fs
-program using the
-.B \-n
-option to print out where the superblocks exist, supposing
-.B mke2fs
+Additional backup superblocks can be determined by using the \fBmke2fs\fR(8)
+program using the \fB\-n\fR
+option to print out where the superblocks exist, supposing \fBmke2fs\fR(8)
is supplied with arguments that are consistent with the file system's layout
(e.g., blocksize, blocks per group,
.BR sparse_super ,
The block number here uses 1\ k units. Thus, if you want to use logical
block 32768 on a file system with 4\ k blocks, use "sb=131072".
.TP
-.BR user_xattr | nouser_xattr
+.BR user_xattr " | " nouser_xattr
Support "user." extended attributes (or not).
enhanced with journaling. It supports the same options as ext2 as
well as the following additions:
.TP
-.BR journal_dev=devnum / journal_path=path
+.B journal_dev=\fIdevnum\fR | \fBjournal_path=\fIpath\fR
When the external journal device's major/minor numbers
have changed, these options allow the user to specify
the new journal location. The journal device is
identified either through its new major/minor numbers encoded
in devnum, or via a path to the device.
.TP
-.BR norecovery / noload
+.BR norecovery " | " noload
Don't load the journal on mounting. Note that
if the file system was not unmounted cleanly,
skipping the journal replay will lead to the
in files after a crash and journal recovery.
.RE
.TP
-.B data_err=ignore
-Just print an error message if an error occurs in a file data buffer in
-ordered mode.
-.TP
-.B data_err=abort
-Abort the journal if an error occurs in a file data buffer in ordered mode.
+.BR data_err= { abort | ignore }
+If an error occurs in a file data buffer in ordered mode:
+.sp
+When \fBdata_err=abort\fR, abort the journal.
+.sp
+When \fBdata_err=ignore\fR, just print an error message.
.TP
-.BR barrier=0 " / " barrier=1
-This disables / enables the use of write barriers in the jbd code. barrier=0
-disables, barrier=1 enables (default). This also requires an IO stack which can
+.BR barrier= { 0 | 1 }
+This disables / enables the use of write barriers in the jbd code. \fBbarrier=0\fR
+disables, \fBbarrier=1\fR enables (default). This also requires an IO stack which can
support barriers, and if jbd gets an error on a barrier write, it will disable
barriers again with a warning. Write barriers enforce proper on-disk ordering
of journal commits, making volatile disk write caches safe to use, at some
manual page.
.TP
.BR jqfmt= { vfsold | vfsv0 | vfsv1 }
-Apart from the old quota system (as in ext2, jqfmt=vfsold aka version 1 quota)
-ext3 also supports journaled quotas (version 2 quota). jqfmt=vfsv0 or
-jqfmt=vfsv1 enables journaled quotas. Journaled quotas have the advantage that
-even after a crash no quota check is required. When the
-.B quota
+Apart from the old quota system (as in ext2, \fBjqfmt=vfsold\fR aka version 1 quota)
+ext3 also supports journaled quotas (version 2 quota). \fBjqfmt=vfsv0\fR or
+\fBjqfmt=vfsv1\fR enables journaled quotas. Journaled quotas have the advantage
+that even after a crash no quota check is required. When the \fBquota\fR
file system feature is enabled, journaled quotas are used automatically, and
this mount option is ignored.
.TP
-.BR usrjquota=aquota.user | grpjquota=aquota.group
-For journaled quotas (jqfmt=vfsv0 or jqfmt=vfsv1), the mount options
-usrjquota=aquota.user and grpjquota=aquota.group are required to tell the
-quota system which quota database files to use. When the
-.B quota
-file system feature is enabled, journaled quotas are used automatically, and
-this mount option is ignored.
+.BR usrjquota=aquota.user " | " grpjquota=aquota.group
+For journaled quotas (\fBjqfmt=vfsv0\fR or \fBjqfmt=vfsv1\fR), the mount
+options \fBusrjquota=aquota.user\fR and \fBgrpjquota=aquota.group\fR are
+required to tell the quota system which quota database files to use. When the
+\fBquota\fR file system feature is enabled, journaled quotas are used
+automatically, and this mount option is ignored.
.SH "Mount options for ext4"
The ext4 file system is an advanced level of the ext3 file system which
file system.
The options
-.B journal_dev, journal_path, norecovery, noload, data, commit, orlov,
-.B oldalloc, [no]user_xattr, [no]acl, bsddf, minixdf, debug, errors,
-.B data_err, grpid, bsdgroups, nogrpid, sysvgroups, resgid, resuid, sb,
-.B quota, noquota, nouid32, grpquota, usrquota, usrjquota, grpjquota,
-.B and jqfmt are backwardly compatible with ext3 or ext2.
-.TP
-.B journal_checksum | nojournal_checksum
+.BR journal_dev ,
+.BR journal_path ,
+.BR norecovery ,
+.BR noload ,
+.BR data ,
+.BR commit ,
+.BR orlov ,
+.BR oldalloc ,
+.RB [ no ] user_xattr ,
+.RB [ no ] acl ,
+.BR bsddf ,
+.BR minixdf ,
+.BR debug ,
+.BR errors ,
+.BR data_err ,
+.BR grpid ,
+.BR bsdgroups ,
+.BR nogrpid ,
+.BR sysvgroups ,
+.BR resgid ,
+.BR resuid ,
+.BR sb ,
+.BR quota ,
+.BR noquota ,
+.BR nouid32 ,
+.BR grpquota ,
+.BR usrquota ,
+.BR usrjquota ,
+.BR grpjquota ", and"
+.B jqfmt
+are backwardly compatible with ext3 or ext2.
+.TP
+.BR journal_checksum " | " nojournal_checksum
The journal_checksum option enables checksumming of the journal transactions.
-This will allow the recovery code in e2fsck and the kernel to detect corruption
-in the kernel. It is a compatible change and will be ignored by older kernels.
+This will allow the recovery code in \fBe2fsck\fR(8) and the kernel to detect
+corruption in the kernel. It is a compatible change and will be ignored by older
+kernels.
.TP
.B journal_async_commit
Commit block can be written to disk without waiting for descriptor blocks. If
enabled older kernels cannot mount the device.
-This will enable 'journal_checksum' internally.
+This will enable \fBjournal_checksum\fR internally.
.TP
-.BR barrier=0 " / " barrier=1 " / " barrier " / " nobarrier
+.BR barrier= { 0 | 1 "} | " barrier " | " nobarrier
These mount options have the same effect as in ext3. The mount options
-"barrier" and "nobarrier" are added for consistency with other ext4 mount
-options.
+\fBbarrier\fR and \fBnobarrier\fR are added for consistency with other
+ext4 mount options.
The ext4 file system enables write barriers by default.
.TP
Disable delayed allocation. Blocks are allocated when data is copied from user
to page cache.
.TP
-.BI max_batch_time= usec
+.BI max_batch_time= max_usec
Maximum amount of time ext4 should wait for additional file system operations to
be batch together with a synchronous write operation. Since a synchronous
write operation is going to force a commit and then a wait for the I/O
complete, it doesn't cost much, and can be a huge throughput win, we wait for a
small amount of time to see if any other transactions can piggyback on the
-synchronous write. The algorithm used is designed to automatically tune for
+synchronous write.
+.sp
+The algorithm used is designed to automatically tune for
the speed of the disk, by measuring the amount of time (on average) that it
takes to finish committing a transaction. Call this time the "commit time".
If the time that the transaction has been running is less than the commit time,
ext4 will try sleeping for the commit time to see if other operations will join
-the transaction. The commit time is capped by the max_batch_time, which
-defaults to 15000\ \[mc]s (15\ ms). This optimization can be turned off entirely by
-setting max_batch_time to 0.
+the transaction. The commit time is capped at \fImax_usec\fR, which
+defaults to 15000\ \[mc]s (15\ ms). This optimization can be turned off entirely
+by setting \fBmax_batch_time=0\fR.
.TP
-.BI min_batch_time= usec
+.BI min_batch_time= min_usec
This parameter sets the commit time (as described above) to be at least
-min_batch_time. It defaults to zero microseconds. Increasing this parameter
+\fImin_usec\fR. It defaults to zero microseconds. Increasing this parameter
may improve the throughput of multi-threaded, synchronous workloads on very
fast disks, at the cost of increasing latency.
.TP
debugging purposes. This is normally used while
remounting a file system which is already mounted.
.TP
-.BR auto_da_alloc | noauto_da_alloc
+.BR auto_da_alloc " | " noauto_da_alloc
Many broken applications don't use fsync() when
replacing existing files via patterns such as
complete as quickly as possible; the inode table initialization process would
then be deferred until the next time the file system is mounted.
.TP
-.B init_itable=n
+.BI init_itable= n
The lazy itable init code will wait n times the number of milliseconds it took
to zero out the previous block group's inode table. This minimizes the impact on
system performance while the file system's inode table is being initialized.
.TP
-.BR discard / nodiscard
+.BR discard " | " nodiscard
Controls whether ext4 should issue discard/TRIM commands to the underlying
block device when blocks are freed. This is useful for SSD devices and
sparse/thinly-provisioned LUNs, but it is off by default until sufficient
testing has been done.
.TP
-.BR block_validity / noblock_validity
+.BR block_validity " | " noblock_validity
This option enables/disables the in-kernel facility for tracking
file system metadata blocks within internal data structures. This allows multi-\c
block allocator and other routines to quickly locate extents which might
overlap with file system metadata blocks. This option is intended for debugging
purposes and since it negatively affects the performance, it is off by default.
.TP
-.BR dioread_lock / dioread_nolock
+.BR dioread_lock " | " dioread_nolock
Controls whether or not ext4 should use the DIO read locking. If the
-dioread_nolock option is specified ext4 will allocate uninitialized extent
+\fBdioread_nolock\fR option is specified ext4 will allocate uninitialized extent
before buffer write and convert the extent to initialized after IO completes.
This approach allows ext4 code to avoid using inode mutex, which improves
scalability on high speed storages. However this does not work with data
-journaling and dioread_nolock option will be ignored with kernel warning.
-Note that dioread_nolock code path is only used for extent-based files.
-Because of the restrictions this options comprises it is off by default
-(e.g.\& dioread_lock).
+journaling and \fBdioread_nolock\fR option will be ignored with kernel warning.
+Note that \fBdioread_nolock\fR code path is only used for extent-based files.
+Because of the restrictions this options comprises, it is off by default
+(e.g.\& \fBdioread_lock\fR).
.TP
-.B max_dir_size_kb=n
+.BI max_dir_size_kb= n
This limits the size of the directories so that any attempt to expand them
beyond the specified limit in kilobytes will cause an ENOSPC error. This is
useful in memory-constrained environments, where a very large directory can
use of mbcache for deduplication adds unnecessary computational overhead.
.TP
.B prjquota
-The prjquota mount option enables project quota support on the file system.
-You need the quota utilities to actually enable and manage the quota system.
-This mount option requires the
-.B project
-file system feature.
+This option enables project quota support on the file system. You need the
+\fBquota\fR(1) utilities to actually enable and manage the quota system.
+This mount option requires the \fBproject\fR file system feature.
.SH FILE ATTRIBUTES
The ext2, ext3, and ext4 file systems support setting the following file
attributes on Linux systems using the
.BR chattr (1)
utility:
-.sp
+.IP
.BR a " \- append only"
-.sp
+.IP
.BR A " \- no atime updates"
-.sp
+.IP
.BR d " \- no dump"
-.sp
+.IP
.BR D " \- synchronous directory updates"
-.sp
+.IP
.BR i " \- immutable"
-.sp
+.IP
.BR S " \- synchronous updates"
-.sp
+.IP
.BR u " \- undeletable"
-.sp
+.P
In addition, the ext3 and ext4 file systems support the following flag:
-.sp
+.IP
.BR j " \- data journaling"
-.sp
+.P
Finally, the ext4 file system also supports the following flag:
-.sp
+.IP
.BR e " \- extents format"
-.sp
+.P
For descriptions of these attribute flags, please refer to the
.BR chattr (1)
man page.
ext4, 5.4
.IP "\fBstable_inodes\fR" 2i
ext4, 5.5
+.IP "\fBfast_commit\fR" 2i
+ext4, 5.10
+.IP "\fBorphan_file\fR" 2i
+ext4, 5.15
.SH SEE ALSO
.BR mke2fs (8),
.BR mke2fs.conf (5),
.I cluster-size
]
[
-.B \-d
-.I root-directory|tarball
+.B \-d\fR \fIroot-directory\fR|\fItarball\fR|\fI-\fR
]
[
.B \-D
.SH OPTIONS
.TP
.BI \-b " block-size"
-Specify the size of blocks in bytes. Valid block-size values are powers of two
-from 1024 up to 65536 (however note that the kernel is able to mount only
-file systems with block-size smaller or equal to the system page size - 4k on
-x86 systems, up to 64k on ppc64 or aarch64 depending on kernel configuration).
-If omitted, block-size is heuristically determined by the file system size and
-the expected usage of the file system (see the
-.B \-T
-option). In most common cases, the default block size is 4k. If
-.I block-size
-is preceded by a negative sign ('-'), then
-.B mke2fs
-will use heuristics to determine the
-appropriate block size, with the constraint that the block size will be
-at least
-.I block-size
-bytes. This is useful for certain hardware devices which require that
-the blocksize be a multiple of 2k.
+Specify the size of blocks in bytes. Valid \fIblock-size\fR values are powers
+of two from 1024 up to 65536 (however note that the kernel is able to mount only
+file systems with \fIblock-size\fR smaller or equal to the system page size - 4k
+on x86 systems, up to 64k on ppc64 or aarch64 depending on kernel configuration).
+If omitted, \fIblock-size\fR is heuristically determined by the file system size
+and the expected usage of the file system (see the \fB\-T\fR option). In most
+common cases, the default block size is 4k. If \fIblock-size\fR is preceded by a
+negative sign ('-'), then \fBmke2fs\fR will use heuristics to determine the
+appropriate block size, with the constraint that the block size will be at least
+\fIblock-size\fR bytes. This is useful for certain hardware devices which require
+that the blocksize be a multiple of 2k.
.TP
.B \-c
Check the device for bad blocks before creating the file system. If
this option is specified twice, then a slower read-write
test is used instead of a fast read-only test.
.TP
-.B \-C " cluster-size"
-Specify the size of cluster in bytes for file systems using the bigalloc
-feature. Valid cluster-size values range from 2 to 32768 times the
-filesystem blocksize and must be a power of 2. The cluster-size can
-only be specified if the bigalloc feature is enabled. (See the
-.B ext4 (5)
-man page for more details about bigalloc.) The default cluster size if
-bigalloc is enabled is 16 times the block size.
+.BI \-C " cluster-size"
+Specify the size of clusters in bytes for file systems using the \fBbigalloc\fR
+feature. Valid \fIcluster-size\fR values range from 2 to 32768 times the
+filesystem block size and must be a power of 2. The \fIcluster-size\fR can
+only be specified if the \fBbigalloc\fR feature is enabled. (See the
+\fBext4\fR(5) man page for more details about \fBbigalloc\fR.) The
+default cluster size if \fBbigalloc\fR is enabled is 16 times the block size.
.TP
-.BI \-d " root-directory|tarball"
+.B \-d\fR \fIroot-directory\fR|\fItarball\fR|\fI-\fR
Copy the contents of the given directory or tarball into the root directory of the
-file system. Tarball input is only available if mke2fs was compiled with
+file system. Tarball input is only available if \fBmke2fs\fR was compiled with
libarchive support enabled and if the libarchive shared library is available
-at run-time. The special value "-" will read a tarball from standard input.
+at run-time. The special value "\fB-\fR" will read a tarball from standard input.
.TP
.B \-D
-Use direct I/O when writing to the disk. This avoids mke2fs dirtying a
+Use direct I/O when writing to the disk. This avoids \fBmke2fs\fR dirtying a
lot of buffer cache memory, which may impact other applications running
-on a busy server. This option will cause mke2fs to run much more
+on a busy server. This option will cause \fBmke2fs\fR to run much more
slowly, however, so there is a tradeoff to using direct I/O.
.TP
.BI \-e " error-behavior"
The following extended options are supported:
.RS 1.2i
.TP
-.B assume_storage_prezeroed\fR[\fB= \fI<0 to disable, 1 to enable>\fR]
-If enabled,
-.BR mke2fs
+.BR assume_storage_prezeroed [ = < 0 " to disable | " 1 " to enable>]
+If enabled, \fBmke2fs\fR
assumes that the storage device has been prezeroed, skips zeroing the journal
and inode tables, and annotates the block group flags to signal that the inode
table has been zeroed.
as default.
.TP
.BI encoding= encoding-name
-Enable the
-.I casefold
-feature in the super block and set
-.I encoding-name
-as the encoding to be used. If
-.I encoding-name
-is not specified, the encoding defined in
-.BR mke2fs.conf (5)
-is used.
+Enable the \fBcasefold\fR feature in the super block and set \fIencoding-name\fR
+as the encoding to be used. If \fIencoding-name\fR is not specified, the
+encoding defined in \fBmke2fs.conf\fR(5) is used.
.TP
.BI encoding_flags= encoding-flags
Define parameters for file name character encoding operations. If a
Use the specified UUID as the seed for hashing, rather than generating a
random seed each time. Intended for use with reproducible builds.
.TP
-.B lazy_itable_init\fR[\fB= \fI<0 to disable, 1 to enable>\fR]
-If enabled and the uninit_bg feature is enabled, the inode table will
-not be fully initialized by
-.BR mke2fs .
-This speeds up file system
+.BR lazy_itable_init [ = < 0 " to disable | " 1 " to enable>]
+If enabled and the \fBuninit_bg\fR feature is enabled, the inode table will
+not be fully initialized by \fBmke2fs\fR. This speeds up file system
initialization noticeably, but it requires the kernel to finish
initializing the file system in the background when the file system is
first mounted. If the option value is omitted, it defaults to 1 to
enable lazy inode table zeroing.
.TP
-.B lazy_journal_init\fR[\fB= \fI<0 to disable, 1 to enable>\fR]
-If enabled, the journal inode will not be fully zeroed out by
-.BR mke2fs .
+.BR lazy_journal_init [ = < 0 " to disable | " 1 " to enable>]
+If enabled, the journal inode will not be fully zeroed out by \fBmke2fs\fR.
This speeds up file system initialization noticeably, but carries some
small risk if the system crashes before the journal has been overwritten
entirely one time. If the option value is omitted, it defaults to 1 to
option. This will disable the copy and leaves the files in the newly
created file system without any extended attributes.
.TP
-.BI num_backup_sb= <0|1|2>
-If the
-.B sparse_super2
+.BR num_backup_sb= < 0 | 1 | 2 >
+If the \fBsparse_super2\fR
file system feature is enabled this option controls whether there will
be 0, 1, or 2 backup superblocks created in the file system.
.TP
.BI orphan_file_size= size
Set size of the file for tracking unlinked but still open inodes and inodes
with truncate in progress. Larger file allows for better scalability, reserving
-a few blocks per cpu is ideal.
+a few blocks per CPU is ideal.
.TP
-.B packed_meta_blocks\fR[\fB= \fI<0 to disable, 1 to enable>\fR]
+.BR packed_meta_blocks [ = < 0 " to disable | " 1 " to enable>]
Place the allocation bitmaps and the inode table at the beginning of the
-disk. This option requires that the flex_bg file system feature to be
+disk. This option requires that the \fBflex_bg\fR file system feature to be
enabled in order for it to have effect, and will also create the journal
at the beginning of the file system. This option is useful for flash
devices that use SLC flash at the beginning of the disk.
can be useful for certain specialized use cases, such as supported
Shingled Drives.
.TP
-.B quotatype
-Specify the which quota types (usrquota, grpquota, prjquota) which
-should be enabled in the created file system. The argument of this
+.B quotatype=\fIquota-type\fR[:...]
+Specify the which quota types (\fIusrquota\fR, \fIgrpquota\fR, \fIprjquota\fR)
+which should be enabled in the created file system. The argument of this
extended option should be a colon separated list. This option has
-effect only if the
-.B quota
-feature is set. The default quota types to be initialized if this
-option is not specified is both user and group quotas. If the project
-feature is enabled that project quotas will be initialized as well.
+effect only if the \fBquota\fR
+feature is set. The default quota types to be initialized if this
+option is not specified is both user and group quotas. If the \fBproject\fR
+feature is enabled then the project quotas will be initialized as well.
.TP
.BI resize= max-online-resize
Reserve enough space so that the block group descriptor table can grow
very early, historical Linux systems. The current default (supported
by all modern Linux systems) is revision 1.
.TP
-.BI root_owner [=uid:gid]
+.B root_owner\fR[\fB=\fIuid:gid\fR]
Specify the numeric user and group ID of the root directory. If no UID:GID
is specified, use the user and group ID of the user running \fBmke2fs\fR.
In \fBmke2fs\fR 1.42 and earlier the UID and GID of the root directory were
and avoid side-effects for users that do not expect the contents of the
file system to change based on the user running \fBmke2fs\fR.
.TP
-.BI root_perms [=permissions]
+.B root_perms\fR[\fB=\fIpermissions\fR]
Specify the root directory permissions in octal format. If no permissions
are specified then the root directory permissions would be set in accordance with
the default filesystem umask.
.I stride-size
file system blocks. This is the number of blocks read or written to disk
before moving to the next disk, which is sometimes referred to as the
-.I chunk size.
-This mostly affects placement of file system metadata like bitmaps at
-.B mke2fs
+.IR "chunk size" .
+This mostly affects placement of file system metadata like bitmaps at \fBmke2fs\fR
time to avoid placing them on a single disk, which can hurt performance.
It may also be used by the block allocator.
.TP
Specify the number of blocks in a block group. There is generally no
reason for the user to ever set this parameter, as the default is optimal
for the file system. (For administrators who are creating
-file systems on RAID arrays, it is preferable to use the
-.I stride
-RAID parameter as part of the
-.B \-E
-option rather than manipulating the number of blocks per group.)
-This option is generally used by developers who
-are developing test cases.
+file systems on RAID arrays, it is preferable to use the \fB \-E stride=\fR
+extended option rather than manipulating the number of blocks per group.)
+This option is generally used by developers who are developing test cases.
.IP
If the bigalloc feature is enabled, the
.B \-g
bytes of space on the disk. The larger the
.I bytes-per-inode
ratio, the fewer inodes will be created. This value generally shouldn't
-be smaller than the blocksize of the file system, since in that case more
+be smaller than the \fIblock-size\fR of the file system, since in that case more
inodes would be made than can ever be used. Be warned that it is not
possible to change this ratio on a file system after it is created, so be
careful deciding the correct value for this parameter. Note that resizing
option to
.B mke2fs
is a much simpler and less error-prone method of checking a disk for bad
-blocks before formatting it, as
-.B mke2fs
-will automatically pass the correct parameters to the
-.B badblocks
-program.
+blocks before formatting it, as \fBmke2fs\fR
+will automatically pass the correct parameters to the \fBbadblocks\fR(8) program.
.TP
.BI \-L " new-volume-label"
Set the volume label for the file system to
by commas, that are to be enabled. To disable a feature, simply
prefix the feature name with a caret ('^') character.
Features with dependencies will not be removed successfully.
-The pseudo-file system feature "none" will clear all file system features.
+The pseudo-file system feature "\fBnone\fR" will clear all file system features.
.sp
For more information about the features which can be set, please see
the manual page
recovery method is desired by experienced users. It causes
.B mke2fs
to reinitialize the superblock and group descriptors, while not
-touching the inode table and the block and inode bitmaps. The
-.B e2fsck
+touching the inode table and the block and inode bitmaps. The \fBe2fsck\fR(8)
program should be run immediately after this option is used, and there
-is no guarantee that any data will be salvageable. Due to the wide
-variety of possible options to
-.B mke2fs
-that affect the on-disk layout, it is critical to specify exactly
-the same format options, such as blocksize, fs-type, feature flags, and
+is no guarantee that any data will be salvageable.
+.sp
+Due to the wide variety of possible options to \fBmke2fs\fR that affect the
+on-disk layout, it is critical to specify exactly the same format options, such
+as \fIblock-size\fR, \fIfs-type\fR, feature flags, and
other tunables when using this option, or the file system will be further
corrupted. In some cases, such as file systems that have been resized,
or have had features enabled after format time, it is impossible to
.BI \-t " fs-type"
Specify the file system type (i.e., ext2, ext3, ext4, etc.) that is
to be created.
-If this option is not specified,
-.B mke2fs
-will pick a default either via how
-the command was run (for example, using a name of the form mkfs.ext2,
-mkfs.ext3, etc.) or via a default as defined by the
-.B /etc/mke2fs.conf
+If this option is not specified, \fBmke2fs\fR will pick a default either via how
+the command was run (for example, using a name of the form \fBmkfs.ext2\fR,
+\fBmkfs.ext3\fR, etc.) or via a default as defined by the \fB/etc/mke2fs.conf\fR
file. This option controls which file system options are used by
-default, based on the
-.B fstypes
-configuration stanza in
-.BR /etc/mke2fs.conf .
+default, based on the \fI[fs_types]\fR configuration stanza in
+\fB/etc/mke2fs.conf\fR.
.sp
If the
.B \-O
.B mke2fs
can choose optimal file system parameters for that use. The usage
types that are supported are defined in the configuration file
-.BR /etc/mke2fs.conf .
-The user may specify one or more usage types
-using a comma separated list.
+\fB/etc/mke2fs.conf\fR(5).
+The user may specify one or more usage types using a comma separated list.
.sp
If this option is is not specified,
.B mke2fs
will use the file system type
.IR floppy .
If the file system size is greater than or equal to 3 but less than
-512 megabytes,
-.BR mke2fs (8)
-will use the file system type
-.IR small .
+512 megabytes, \fBmke2fs\fR will use the file system type \fIsmall\fR.
If the file system size is greater than or equal to 4 terabytes but less than
-16 terabytes,
-.BR mke2fs (8)
-will use the file system type
-.IR big .
+16 terabytes, \fBmke2fs\fR will use the file system type \fIbig\fR.
If the file system size is greater than or equal to 16 terabytes,
-.BR mke2fs (8)
-will use the file system type
-.IR huge .
-Otherwise,
-.BR mke2fs (8)
-will use the default file system type
-.IR default .
+\fBmke2fs\fR will use the file system type \fIhuge\fR.
+Otherwise, \fBmke2fs\fR will use the default file system type \fIdefault\fR.
.TP
.BI \-U " UUID"
Set the universally unique identifier (UUID) of the file system to
parameter may also be one of the following:
.RS 1.2i
.TP
-.I clear
+.B clear
clear the file system UUID
.TP
-.I random
+.B random
generate a new randomly-generated UUID
.TP
-.I time
+.B time
generate a new time-based UUID
.RE
.TP
.TP
.BI \-z " undo_file"
Before overwriting a file system block, write the old contents of the block to
-an undo file. This undo file can be used with e2undo(8) to restore the old
+an undo file. This undo file can be used with \fBe2undo\fR(8) to restore the old
contents of the file system should something go wrong. If the empty string is
passed as the undo_file argument, the undo file will be written to a file named
mke2fs-\fIdevice\fR.e2undo in the directory specified via the
-\fIE2FSPROGS_UNDO_DIR\fR environment variable or the \fIundo_dir\fR directive
+\fBE2FSPROGS_UNDO_DIR\fR environment variable or the \fIundo_dir\fR directive
in the configuration file.
-
-WARNING: The undo file cannot be used to recover from a power or system crash.
+.sp
+.B WARNING:
+The undo file cannot be used to recover from a power or system crash.
.SH ENVIRONMENT
.TP
.B MKE2FS_SYNC
document.
.TP
.I [options]
-Contains relations which influence how mke2fs behaves.
+Contains relations which influence how \fBmke2fs\fR(8) behaves.
.TP
.I [defaults]
Contains relations which define the default parameters
used by
.BR mke2fs (8).
In general, these defaults may be overridden by a definition in the
-.B fs_types
-stanza, or by a command-line option provided by the user.
+\fI[fs_types]\fR stanza, or by a command-line option provided by the user.
.TP
.I [fs_types]
Contains relations which define defaults that should be used for specific
file system and usage types. The file system type and usage type can be
-specified explicitly using
-the
-.BR \-t and \-T
-options to
-.BR mke2fs (8),
-respectively.
+specified explicitly using the \fB\-t\fR and \fB\-T\fR options to
+\fBmke2fs\fR(8), respectively.
.TP
.I [devices]
Contains relations which define defaults for specific devices.
stanza.
.TP
.I proceed_delay
-If this relation is set to a positive integer, then mke2fs will
-wait
-.I proceed_delay
-seconds after asking the user for permission to proceed and
+If this relation is set to a positive integer, then \fBmke2fs\fR(8) will wait
+.\fIproceed_delay\fR seconds after asking the user for permission to proceed and
then continue, even if the
user has not answered the question. Defaults to 0, which means to wait
until the user answers the question one way or another.
.TP
.I sync_kludge
If this relation is set to a positive integer, then while writing the
-inode table, mke2fs will request the operating system flush out pending
+inode table, \fBmke2fs\fR(8) will request the operating system flush out pending
writes to initialize the inode table every
.I sync_kludge
block groups. This is needed to work around buggy kernels that don't
.I creator_os
This relation specifies the "creator operating system" for the
file system unless it is overridden on the command line.
-The default value is the OS for which the
-.B mke2fs
-executable was compiled.
+The default value is the OS for which the \fBmke2fs\fR(8) executable was compiled.
.TP
.I fs_type
This relation specifies the default file system type if the user does not
-specify it via the
-.B \-t
-option, or if
-.B mke2fs
-is not started using a program name of the form
-.BI mkfs. fs-type\fR.
-If both the user and the
-.B mke2fs.conf
-file do not specify a default file system type, mke2fs will use a
-default file system type of
-.I ext3
-if a journal was requested via a command-line option, or
-.I ext2
-if not.
+specify it via the \fB\-t\fR option, or if \fBmke2fs\fR(8)
+is not started using a program name of the form \fBmkfs.\fIfs-type\fR.
+If both the user and the \fImke2fs.conf\fR
+file do not specify a default file system type, \fBmke2fs\fR will use a
+default file system type of \fIext3\fR
+if a journal was requested via a command-line option, or \fIext2\fR if not.
.TP
.I undo_dir
This relation specifies the directory where the undo file should be
stored. It can be overridden via the
.B E2FSPROGS_UNDO_DIR
environment variable. If the directory location is set to the value
-.IR none ,
-.B mke2fs
-will not create an undo file.
+\fInone\fR, \fBmke2fs\fR(8) will not create an undo file.
.PP
In addition, any tags that can be specified in a per-file system tags
subsection as defined below (e.g.,
.BR mke2fs (8),
respectively.
.P
-The
-.B mke2fs
+The \fBmke2fs\fR(8)
program constructs a list of fs_types by concatenating the file system
type (i.e., ext2, ext3, etc.) with the usage type list. For most
-configuration options,
-.B mke2fs
-will look for a subsection in the
-.I [fs_types]
+configuration options, \fBmke2fs\fR(8) will look for a subsection in the
+\fI[fs_types]\fR
stanza corresponding with each entry in the constructed list, with later
entries overriding earlier file system or usage types.
-For
-example, consider the following
-.B mke2fs.conf
-fragment:
+For example, consider the following \fImke2fs.conf\fR fragment:
.P
[defaults]
.br
.BR mke2fs.ext4 ,
then the file system type of ext4 will be used. If the file system is
smaller than 3 megabytes, and no usage type is specified, then
-.B mke2fs
-will use a default
-usage type of
-.IR floppy .
-This results in an fs_types list of "ext4, floppy". Both the ext4
-subsection and the floppy subsection define an
-.I inode_size
-relation, but since the later entries in the fs_types list supersede
-earlier ones, the configuration parameter for fs_types.floppy.inode_size
+\fBmke2fs\fR will use a default usage type of \fIfloppy\fR.
+This results in an fs_types list of "ext4, floppy". Both the ext4
+subsection and the floppy subsection define an \fIinode_size\fR
+relation, but since the later entries in the \fI[fs_types]\fR list supersede
+earlier ones, the configuration parameter for \fIfs_types.floppy.inode_size\fR
will be used, so the file system will have an inode size of 128.
.P
The exception to this resolution is the
.I features
tag, which specifies a set of changes to the features used by the
file system, and which is cumulative. So in the above example, first
-the configuration relation defaults.base_features would enable an
-initial feature set with the sparse_super, filetype, resize_inode, and
-dir_index features enabled. Then configuration relation
-fs_types.ext4.features would enable the extents and flex_bg
+the configuration relation \fIdefaults.base_features\fR would enable an
+initial feature set with the
+.BR sparse_super ,
+.BR filetype ,
+.BR resize_inode ", and"
+.B dir_index
+features enabled. Then configuration relation
+\fIfs_types.ext4.features\fR would enable the \fBextents\fR and \fBflex_bg\fR
features, and finally the configuration relation
-fs_types.floppy.features would remove
-the resize_inode feature, resulting in a file system feature set
-consisting of the sparse_super, filetype, dir_index,
-extents_and flex_bg features.
+\fIfs_types.floppy.features\fR would remove
+the \fBresize_inode\fR feature, resulting in a file system feature set
+consisting of the
+.BR sparse_super ,
+.BR filetype ,
+.BR dir_index ,
+.BR extents " and"
+.B flex_bg
+features.
.P
For each file system type, the following tags may be used in that
fs_type's subsection. These tags may also be used in the
command-line option to
.BR mke2fs (8);
that is, a feature can be prefixed by a caret ('^') symbol to disable
-a named feature. Each
-.I feature
-relation specified in the fs_types list will be applied in the order
-found in the fs_types list.
+a named feature. Each \fIfeatures\fR
+relation specified in the \fI[fs_types]\fR list will be applied in the order
+found in the \fI[fs_types]\fR list.
.TP
.I force_undo
This boolean relation, if set to a value of true, forces
.BR mke2fs (8).
.TP
.I auto_64-bit_support
-This relation is a boolean which specifies whether
-.BR mke2fs (8)
-should automatically add the 64bit feature if the number of blocks for
-the file system requires this feature to be enabled. The resize_inode
+This relation is a boolean which specifies whether \fBmke2fs\fR(8)
+should automatically add the \fB64bit\fR feature if the number of blocks for
+the file system requires this feature to be enabled. \fBThe resize_inode\fR
feature is also automatically disabled since it doesn't support 64-bit
block numbers.
.TP
.BR tune2fs (8).
.TP
.I blocksize
-This relation specifies the default blocksize if the user does not
-specify a blocksize on the command line.
+This relation specifies the default block size if the user does not
+specify a block size on the command line.
.TP
.I lazy_itable_init
This boolean relation specifies whether the inode table should
be lazily initialized. It only has meaning if the uninit_bg feature is
-enabled. If lazy_itable_init is true and the uninit_bg feature is
-enabled, the inode table will
-not be fully initialized by
-.BR mke2fs (8).
+enabled. If \fIlazy_itable_init\fR is true and the \fBuninit_bg\fR feature is
+enabled, the inode table will not be fully initialized by \fBmke2fs\fR(8).
This speeds up file system
initialization noticeably, but it requires the kernel to finish
initializing the file system in the background when the file system is
.TP
.I lazy_journal_init
This boolean relation specifies whether the journal inode should be
-lazily initialized. It only has meaning if the has_journal feature is
-enabled. If lazy_journal_init is true, the journal inode will not be
-fully zeroed out by
-.BR mke2fs .
+lazily initialized. It only has meaning if the \fBhas_journal\fR feature is
+enabled. If \fIlazy_journal_init\fR is true, the journal inode will not be
+fully zeroed out by \fBmke2fs\fR.
This speeds up file system initialization noticeably, but carries some
small risk if the system crashes before the journal has been overwritten
entirely one time.
together to create one large virtual block group on an ext4 file system.
This improves meta-data locality and performance on meta-data heavy
workloads. The number of groups must be a power of 2 and may only be
-specified if the flex_bg file system feature is enabled.
+specified if the \fBflex_bg\fR file system feature is enabled.
.TP
.I options
This relation specifies additional extended options which should be
.IR disk .
.TP
.I cluster_size
-This relation specifies the default cluster size if the bigalloc file
+This relation specifies the default cluster size if the \fBbigalloc\fR file
system feature is enabled. It can be overridden via the
.B \-C
command line option to
.I hugefiles_align_disk
This relations specifies whether the alignment should be relative to the
beginning of the hard drive (assuming that the starting offset of the
-partition is available to mke2fs). The default value is false, which
+partition is available to \fBmke2fs\fR(8)). The default value is false, which
will cause hugefile alignment to be relative to the beginning of the
file system.
.TP
huge file number.
.TP
.I warn_y2038_dates
-This boolean relation specifies whether mke2fs will issue a warning
+This boolean relation specifies whether \fBmke2fs\fR(8) will issue a warning
when creating a file system with 128 byte inodes (and so therefore will
not support dates after January 19th, 2038). The default value is true,
except for file systems created for the GNU Hurd since it only supports
when using journaled file systems.
.sp
Mount-count-dependent checking is disabled by default to avoid
-unanticipated long reboots while e2fsck does its work. If you
+unanticipated long reboots while \fBe2fsck\fR(8) does its work. If you
are concerned about file system corruptions caused by potential hardware
problems of kernel bugs, a better solution than mount-count-dependent
checking is to use the
.B clear_mmp
Reset the MMP block (if any) back to the clean state. Use only if
absolutely certain the device is not currently mounted or being
-fscked, or major file system corruption can result. Needs '\-f'.
+fscked, or major file system corruption can result. Needs \fB\-f\fR.
.TP
.BI encoding= encoding-name
-Enable the
-.I casefold
-feature in the super block and set
-.I encoding-name
-as the encoding to be used. If
-.I encoding-name
-is not specified, utf8 is used. The encoding cannot be altered if casefold
+Enable the \fBcasefold\fR feature in the super block and set
+\fIencoding-name\fR as the encoding to be used. If \fIencoding-name\fR
+is not specified, "utf8" is used. The encoding cannot be altered if \fBcasefold\fR
was previously enabled.
.TP
.BI encoding_flags= encoding-flags
flag is not changed using this parameter, its default value is used.
.I encoding-flags
should be a comma-separated lists of flags to be enabled. The flags cannot be
-altered if casefold was previously enabled.
+altered if \fBcasefold\fR was previously enabled.
The only flag that can be set right now is
.I strict
.BI hash_alg= hash-alg
Set the default hash algorithm used for file systems with hashed b-tree
directories. Valid algorithms accepted are:
-.IR legacy ,
-.IR half_md4 ,
+.BR legacy ,
+.BR half_md4 ,
and
-.IR tea .
+.BR tea .
.TP
.BI mmp_update_interval= interval
Adjust the initial MMP update interval to
.BI orphan_file_size= size
Set size of the file for tracking unlinked but still open inodes and inodes
with truncate in progress. Larger file allows for better scalability, reserving
-a few blocks per cpu is ideal.
+a few blocks per CPU is ideal.
.TP
.BI stride= stride-size
Configure the file system for a RAID array with
.I stride-size
file system blocks. This is the number of blocks read or written to disk
before moving to next disk. This mostly affects placement of file system
-metadata like bitmaps at
-.BR mke2fs (2)
+metadata like bitmaps at \fBmke2fs\fR(8)
time to avoid placing them on a single disk, which can hurt the performance.
It may also be used by block allocator.
.TP
.RE
.TP
.B \-f
-Force the tune2fs operation to complete even in the face of errors. This
-option is useful when removing the
-.B has_journal
+Force the \fBtune2fs\fR operation to complete even in the face of errors. This
+option is useful when removing the \fBhas_journal\fR
file system feature from a file system which has
an external journal (or is corrupted
such that it appears to have an external journal), but that
.B \-f
flag must be specified twice to proceed.
.sp
-.B WARNING:
+.B Warning:
Removing an external journal from a file system which was not cleanly unmounted
without first replaying the external journal can result in
severe data loss and file system corruption.
files to the invisible, reserved journal inode. For all file systems
except for the root file system, this should happen automatically and
naturally during the next reboot cycle. Since the root file system is
-mounted read-only,
-.BR e2fsck (8)
+mounted read-only, \fBe2fsck\fR(8)
must be run from a rescue floppy in order to effect this transition.
.IP
On some distributions, such as Debian, if an initial ramdisk is used,
the initrd scripts will automatically convert an ext2 root file system
-to ext3 if the
-.B /etc/fstab
+to ext3 if the \fB/etc/fstab\fR(5)
file specifies the ext3 file system for the root file system in order to
avoid requiring the use of a rescue floppy to add an ext3 journal to
the root file system.
is longer than 16 characters,
.B tune2fs
will truncate it and print a warning. For other file systems that
-support online label manipulation and are mounted
-.B tune2fs
-will work as well, but it will not attempt to truncate the
-.I volume-label
-at all. The volume label can be used by
-.BR mount (8),
-.BR fsck (8),
-and
-.BR /etc/fstab (5)
-(and possibly others) by specifying
-.BI LABEL= volume-label
-instead of a block special device name like
-.BR /dev/hda5 .
+support online label manipulation and are mounted \fBtune2fs\fR
+will work as well, but it will not attempt to truncate the \fIvolume-label\fR
+at all. The volume label can be used by \fBmount\fR(8), \fBfsck\fR(8),
+and \fB/etc/fstab\fR(5) (and possibly others) by specifying
+\fBLABEL=\fIvolume-label\fR instead of a block special device name like
+\fI/dev/hda5\fR.
.TP
.BI \-m " reserved-blocks-percentage"
Set the percentage of the file system which may only be allocated
kernels.)
.TP
.B discard
-The file system will be mounted with the discard mount option. This will
+The file system will be mounted with the \fBdiscard\fR mount option. This will
cause the file system driver to attempt to use the trim/discard feature
of some storage devices (such as SSD's and thin-provisioned drives
available in some enterprise storage arrays) to inform the storage
system driver in 2.6.35+ kernels.)
.TP
.B nodelalloc
-The file system will be mounted with the nodelalloc mount option. This
+The file system will be mounted with the \fBnodelalloc\fR mount option. This
will disable the delayed allocation feature. (This option is currently
only supported by the ext4 file system driver in 2.6.35+ kernels.)
.RE
Allow the value of each extended attribute to be placed in the data blocks of a
separate inode if necessary, increasing the limit on the size and number of
extended attributes per file.
-.B Tune2fs
-currently only supports setting this file system feature.
+\fBtune2fs\fR currently only supports setting this file system feature.
.TP
.B encrypt
Enable support for file system level encryption.
-.B Tune2fs
-currently only supports setting this file system feature.
+\fBtune2fs\fR currently only supports setting this file system feature.
.TP
.B extent
Enable the use of extent trees to store the location of data blocks in inodes.
-.B Tune2fs
-currently only supports setting this file system feature.
+\fBtune2fs\fR currently only supports setting this file system feature.
.TP
.B extra_isize
Enable the extended inode fields used by ext4.
.TP
.B flex_bg
Allow bitmaps and inode tables for a block group to be placed
-anywhere on the storage media. \fBTune2fs\fR will not reorganize
-the location of the inode tables and allocation bitmaps, as
-.BR mke2fs (8)
-will do when it creates a freshly formatted file system with
-.B flex_bg
+anywhere on the storage media. \fBtune2fs\fR will not reorganize
+the location of the inode tables and allocation bitmaps, as \fBmke2fs\fR(8)
+will do when it creates a freshly formatted file system with \fBflex_bg\fR
enabled.
.TP
.B has_journal
.TP
.B large_dir
Increase the limit on the number of files per directory.
-.B Tune2fs
-currently only supports setting this file system feature.
+\fBtune2fs\fR currently only supports setting this file system feature.
.TP
.B huge_file
Support files larger than 2 terabytes in size.
Force the kernel to mount the file system read-only.
.TP
.B resize_inode
-Reserve space so the block group descriptor table may grow in the
-future.
-.B Tune2fs
-only supports clearing this file system feature.
+Reserve space so the block group descriptor table may grow in the future.
+\fBtune2fs\fR only supports clearing this file system feature.
.TP
.B sparse_super
Limit the number of backup superblocks to save space on large file systems.
-.B Tune2fs
-currently only supports setting this file system feature.
+\fBtune2fs\fR currently only supports setting this file system feature.
.TP
.B stable_inodes
Prevent the file system from being shrunk or having its UUID changed, in order to
allow the use of specialized encryption settings that make use of the inode
numbers and UUID.
-.B Tune2fs
-currently only supports setting this file system feature.
+\fBtune2fs\fR currently only supports setting this file system feature.
.TP
.B uninit_bg
Allow the kernel to initialize bitmaps and inode tables lazily, and to
keep a high watermark for the unused inodes in a file system, to reduce
-.BR e2fsck (8)
-time. The first e2fsck run after enabling this feature will take the
-full time, but subsequent e2fsck runs will take only a fraction of the
+\fBe2fsck\fR(8)
+time. The first \fBe2fsck\fR(8) run after enabling this feature will take the
+full time, but subsequent \fBe2fsck\fR(8) runs will take only a fraction of the
original time, depending on how full the file system is.
.TP
.B verity
Enable support for verity protected files.
-.B Tune2fs
-currently only supports setting this file system feature.
+\fBtune2fs\fR currently only supports setting this file system feature.
.RE
.IP
After setting or clearing
Set the number of reserved file system blocks.
.TP
.BI \-Q " quota-options"
-Sets 'quota' feature on the superblock and works on the quota files for the
+Sets the \fBquota\fR feature on the superblock and works on the quota files for the
given quota type. Quota options could be one or more of the following:
.RS 1.2i
.TP
-.B [^]usrquota
+.RB [ ^ ] usrquota
Sets/clears user quota inode in the superblock.
.TP
-.B [^]grpquota
+.RB [ ^ ] grpquota
Sets/clears group quota inode in the superblock.
.TP
-.B [^]prjquota
+.RB [ ^ ] prjquota
Sets/clears project quota inode in the superblock.
.RE
.TP
parameter may also be one of the following:
.RS 1.2i
.TP
-.I clear
+.B clear
clear the file system UUID
.TP
-.I random
+.B random
generate a new randomly-generated UUID
.TP
-.I time
+.B time
generate a new time-based UUID
.RE
.IP
.BR fsck (8),
and
.BR /etc/fstab (5)
-(and possibly others) by specifying
-.BI UUID= uuid
-instead of a block special device name like
-.BR /dev/hda1 .
+(and possibly others) by specifying \fBUUID=\fIuuid\fR
+instead of a block special device name like \fI/dev/hda1\fR.
.IP
See
.BR uuidgen (8)
.TP
.BI \-z " undo_file"
Before overwriting a file system block, write the old contents of the block to
-an undo file. This undo file can be used with e2undo(8) to restore the old
+an undo file. This undo file can be used with \fBe2undo\fR(8) to restore the old
contents of the file system should something go wrong. If the empty string is
-passed as the undo_file argument, the undo file will be written to a file named
-tune2fs-\fIdevice\fR.e2undo in the directory specified via the
-\fIE2FSPROGS_UNDO_DIR\fR environment variable.
-
-WARNING: The undo file cannot be used to recover from a power or system crash.
+passed as the \fIundo_file\fR argument, the undo file will be written to a file
+named tune2fs-\fIdevice\fR.e2undo in the directory specified via the
+\fBE2FSPROGS_UNDO_DIR\fR environment variable.
+.sp
+.B WARNING:
+The undo file cannot be used to recover from a power or system crash.
.SH BUGS
We haven't found any bugs yet. That doesn't mean there aren't any...
.SH AUTHOR
projects / thirdparty / e2fsprogs.git / commitdiff
