.\" -*- nroff -*-
.\" Copyright 2006 by Theodore Ts'o. All Rights Reserved.
.\" This file may be copied under the terms of the GNU Public License.
-.\"
+.\"
.TH mke2fs.conf 5 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
mke2fs.conf \- Configuration file for mke2fs
.SH DESCRIPTION
.I mke2fs.conf
-is the configuration file for
-.BR mke2fs (8).
-It controls the default parameters used by
+is the configuration file for
+.BR mke2fs (8).
+It controls the default parameters used by
.BR mke2fs (8)
-when it is creating ext2 or ext3 filesystems.
+when it is creating ext2, ext3, or ext4 file systems.
.PP
The
.I mke2fs.conf
-file uses an INI-style format. Stanzas, or top-level sections, are
-delimited by square braces: [ ]. Within each section, each line
+file uses an INI-style format. Stanzas, or top-level sections, are
+delimited by square braces: [ ]. Within each section, each line
defines a relation, which assigns tags to values, or to a subsection,
-which contains further relations or subsections.
+which contains further relations or subsections.
.\" Tags can be assigned multiple values
-An example of the INI-style format used by this configuration file
+An example of the INI-style format used by this configuration file
follows below:
.P
[section1]
.br
}
.P
-Comments are delimited by a semicolon (';') or a hash ('#') character
-at the beginning of the comment, and are terminated by the end of
+Comments are delimited by a semicolon (';') or a hash ('#') character
+at the beginning of the comment, and are terminated by the end of
line character.
.P
Tags and values must be quoted using double quotes if they contain
-spaces. Within a quoted string, the standard backslash interpretations
-apply: "\en" (for the newline character),
-"\et" (for the tab character), "\eb" (for the backspace character),
+spaces. Within a quoted string, the standard backslash interpretations
+apply: "\en" (for the newline character),
+"\et" (for the tab character), "\eb" (for the backspace character),
and "\e\e" (for the backslash character).
.P
Some relations expect a boolean value. The parser is quite liberal on
boolean true value, and ``no'', ``n'', ``false'', ``nil'', ``0'',
``off'' as a boolean false value.
.P
-The following stanzas are used in the
+The following stanzas are used in the
.I mke2fs.conf
file. They will be described in more detail in future sections of this
document.
-.TP
+.TP
+.I [options]
+Contains relations which influence how mke2fs 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 an command-line option provided by the user.
-.TP
+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
-filesystem types. The filesystem type can be specified explicitly using
-the
-.B -T
-option to
-.BR mke2fs (8).
-.SH THE [defaults] STANZA
-The following relations are defined in the
-.I [defaults]
-stanza.
-.TP
-.I base_features
-This relation specifies the filesystems features which are enabled in
-newly created filesystems. It may be overridden by the
-.I base_features
-relation found in the filesystem or usage type subsection of
+file system and usage types. The file system type and usage type can be
+specified explicitly using
the
-.I [fs_types]
+.BR \-t and \-T
+options to
+.BR mke2fs (8),
+respectively.
+.TP
+.I [devices]
+Contains relations which define defaults for specific devices.
+.SH THE [options] STANZA
+The following relations are defined in the
+.I [options]
stanza.
.TP
-.I default_features
-This relation specifies a set of features that should be added or
-removed to the features listed in the
-.I base_features
-relation. It may be overridden by the filesystem-specific
-.I default_features
-in the filesystem or usage type subsection of
-.IR [fs_types] ,
-and by the
-.B -O
-command-line option
-to
-.BR mke2fs (8).
+.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
+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 enable_periodic_fsck
-This boolean relation specifies whether periodic filesystem checks should be
-enforced at boot time. If set to true, checks will be forced every
-180 days, or after a random number of mounts. These values may
-be changed later via the
-.B -i
-and
-.B -c
-command-line options to
-.BR tune2fs (8).
+.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
+writes to initialize the inode table every
+.I sync_kludge
+block groups. This is needed to work around buggy kernels that don't
+handle writeback throttling correctly.
+.SH THE [defaults] STANZA
+The following relations are defined in the
+.I [defaults]
+stanza.
.TP
-.I force_undo
-This boolean relation, if set to a value of true, forces
+.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
-to always try to create an undo file, even if the undo file might be
-huge and it might extend the time to create the filesystem image
-because the inode table isn't being initialized lazily.
+executable was compiled.
.TP
.I fs_type
-This relation specifies the default filesystem type if the user does not
+This relation specifies the default file system type if the user does not
specify it via the
.B \-t
option, or if
.BI mkfs. fs-type\fR.
If both the user and the
.B mke2fs.conf
-file does not specify a default filesystem type, mke2fs will use a
-default filesystem type of
-.IR ext3
+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.
.TP
-.I blocksize
-This relation specifies the default blocksize if the user does not
-specify a blocksize on the command line, and the filesystem-type
-specific section of the configuration file does not specify a blocksize.
-.TP
-.I hash_alg
-This relation specifies the default hash algorithm used for the
-new filesystems with hashed b-tree directories. Valid algorithms
-accepted are:
-.IR legacy ,
-.IR half_md4 ,
-and
-.IR tea .
-.TP
-.I inode_ratio
-This relation specifies the default inode ratio if the user does not
-specify one on the command line, and the filesystem-type
-specific section of the configuration file does not specify a default
-inode ratio.
-.TP
-.I inode_size
-This relation specifies the default inode size if the user does not
-specify one on the command line, and the filesystem-type
-specific section of the configuration file does not specify a default
-inode size.
-.TP
-.I reserved_ratio
-This relation specifies the default percentage of filesystem blocks
-reserved for the super-user, if the user does not
-specify one on the command line, and the filesystem-type
-specific section of the configuration file does not specify a default
-reserved ratio. This value can be a floating point number.
-.TP
.I undo_dir
This relation specifies the directory where the undo file should be
stored. It can be overridden via the
.IR none ,
.B mke2fs
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.,
+.IR blocksize ,
+.IR hash_alg ,
+.IR inode_ratio ,
+.IR inode_size ,
+.IR reserved_ratio ,
+etc.) can also be specified in the
+.I defaults
+stanza to specify the default value to be used if the user does not
+specify one on the command line, and the file system-type
+specific section of the configuration file does not specify a default value.
.SH THE [fs_types] STANZA
Each tag in the
-.I [fs_types]
-stanza names a filesystem type or usage type which can be specified via the
+.I [fs_types]
+stanza names a file system type or usage type which can be specified via the
.B \-t
or
.B \-T
.P
The
.B mke2fs
-program constructs a list of fs_types by concatenating the filesystem
+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]
stanza corresponding with each entry in the constructed list, with later
-entries overriding earlier filesystem or usage types.
+entries overriding earlier file system or usage types.
For
example, consider the following
.B mke2fs.conf
.P
If mke2fs started with a program name of
.BR mke2fs.ext4 ,
-then the filesystem type of ext4 will be used. If the filesystem is
+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
.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
-will be used, so the filesystem will have an inode size of 128.
+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 is specifies a set of changes to the features used by the
-filesystem, and which is cumulative. So in the above example, first
+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
features, and finally the configuration relation
fs_types.floppy.features would remove
-the resize_inode feature, resulting in a filesystem feature set
-consisting of the sparse_super, filetype, resize_inode, dir_index,
+the resize_inode feature, resulting in a file system feature set
+consisting of the sparse_super, filetype, dir_index,
extents_and flex_bg features.
.P
-For each filesystem type, the following tags may be used in that
-fs_type's subsection:
+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
+.I default
+section:
.TP
.I base_features
This relation specifies the features which are initially enabled for this
-filesystem type. Only one
+file system type. Only one
.I base_features
will be used, so if there are multiple entries in the fs_types list
whose subsections define the
relation, only the last will be used by
.BR mke2fs (8).
.TP
+.I enable_periodic_fsck
+This boolean relation specifies whether periodic file system checks should be
+enforced at boot time. If set to true, checks will be forced every
+180 days, or after a random number of mounts. These values may
+be changed later via the
+.B -i
+and
+.B -c
+command-line options to
+.BR tune2fs (8).
+.TP
+.I errors
+Change the behavior of the kernel code when errors are detected.
+In all cases, a file system error will cause
+.BR e2fsck (8)
+to check the file system on the next boot.
+.I errors
+can be one of the following:
+.RS 1.2i
+.TP 1.2i
+.B continue
+Continue normal execution.
+.TP
+.B remount-ro
+Remount file system read-only.
+.TP
+.B panic
+Cause a kernel panic.
+.RE
+.TP
.I features
This relation specifies a comma-separated list of features edit
requests which modify the feature set
-used by the newly constructed filesystem. The syntax is the same as the
+used by the newly constructed file system. The syntax is the same as the
.B -O
command-line option to
.BR mke2fs (8);
relation specified in the fs_types list will be applied in the order
found in the fs_types list.
.TP
+.I force_undo
+This boolean relation, if set to a value of true, forces
+.B mke2fs
+to always try to create an undo file, even if the undo file might be
+huge and it might extend the time to create the file system image
+because the inode table isn't being initialized lazily.
+.TP
.I default_features
-This relation specifies set of features which should be enabled or
+This relation specifies set of features which should be enabled or
disabled after applying the features listed in the
.I base_features
and
specify a blocksize on the command line.
.TP
.I lazy_itable_init
-This boolean relation specifies whether the inode table should
+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 fully initialized by
+not be fully initialized by
.BR mke2fs (8).
-This speeds up filesystem
+This speeds up file system
initialization noticeably, but it requires the kernel to finish
-initializing the filesystem in the background when the filesystem is
+initializing the file system in the background when the file system is
first mounted.
.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 .
+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.
+.TP
+.I journal_location
+This relation specifies the location of the journal.
+.TP
+.I num_backup_sb
+This relation indicates whether file systems with the
+.B sparse_super2
+feature enabled should be created with 0, 1, or 2 backup superblocks.
+.TP
+.I packed_meta_blocks
+This boolean relation specifies whether the allocation bitmaps, inode
+table, and journal should be located at the beginning of the file system.
+.TP
.I inode_ratio
This relation specifies the default inode ratio if the user does not
specify one on the command line.
specify one on the command line.
.TP
.I reserved_ratio
-This relation specifies the default percentage of filesystem blocks
+This relation specifies the default percentage of file system blocks
reserved for the super-user, if the user does not specify one on the command
line.
.TP
.I hash_alg
This relation specifies the default hash algorithm used for the
-new filesystems with hashed b-tree directories. Valid algorithms
+new file systems with hashed b-tree directories. Valid algorithms
accepted are:
.IR legacy ,
.IR half_md4 ,
.TP
.I flex_bg_size
This relation specifies the number of block groups that will be packed
-together to create one large virtual block group on an ext4 filesystem.
+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 filesystem feature is enabled.
+specified if the flex_bg file system feature is enabled.
.TP
.I options
This relation specifies additional extended options which should be
option. This can be used to configure the default extended options used
by
.BR mke2fs (8)
-on a per-filesystem type basis.
+on a per-file system type basis.
.TP
.I discard
This boolean relation specifies whether the
.BR mke2fs (8)
-should attempt to discard device prior to filesystem creation.
+should attempt to discard device prior to file system creation.
.TP
.I cluster_size
This relation specifies the default cluster size if the bigalloc file
.B \-C
command line option to
.BR mke2fs (8)
+.TP
+.I make_hugefiles
+This boolean relation enables the creation of pre-allocated files as
+part of formatting the file system. The extent tree blocks for these
+pre-allocated files will be placed near the beginning of the file
+system, so that if all of the other metadata blocks are also configured
+to be placed near the beginning of the file system (by disabling the
+backup superblocks, using the packed_meta_blocks option, etc.), the data
+blocks of the pre-allocated files will be contiguous.
+.TP
+.I hugefiles_dir
+This relation specifies the directory where huge files are created,
+relative to the file system root.
+.TP
+.I hugefiles_uid
+This relation controls the user ownership for all of the files and
+directories created by the
+.I make_hugefiles
+feature.
+.TP
+.I hugefiles_gid
+This relation controls the group ownership for all of the files and
+directories created by the
+.I make_hugefiles
+feature.
+.TP
+.I hugefiles_umask
+This relation specifies the umask used when creating the files and
+directories by the
+.I make_hugefiles
+feature.
+.TP
+.I num_hugefiles
+This relation specifies the number of huge files to be created. If this
+relation is not specified, or is set to zero, and the
+.I hugefiles_size
+relation is non-zero, then
+.I make_hugefiles
+will create as many huge files as can fit to fill the entire file system.
+.TP
+.I hugefiles_slack
+This relation specifies how much space should be reserved for other
+files.
+.TP
+.I hugefiles_size
+This relation specifies the size of the huge files. If this relation is
+not specified, the default is to fill the entire file system.
+.TP
+.I hugefiles_align
+This relation specifies the alignment for the start block of the huge
+files. It also forces the size of huge files to be a multiple of the
+requested alignment. If this relation is not specified, no alignment
+requirement will be imposed on the huge files.
+.TP
+.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
+will cause hugefile alignment to be relative to the beginning of the
+file system.
+.TP
+.I hugefiles_name
+This relation specifies the base file name for the huge files.
+.TP
+.I hugefiles_digits
+This relation specifies the (zero-padded) width of the field for the
+huge file number.
+.TP
+.I warn_y2038_dates
+This boolean relation specifies whether mke2fs 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
+128-byte inodes.
+.TP
+.I zero_hugefiles
+This boolean relation specifies whether or not zero blocks will be
+written to the hugefiles while
+.BR mke2fs (8)
+is creating them. By default, zero blocks will be written to the huge
+files to avoid stale data from being made available to potentially
+untrusted user programs, unless the device supports a discard/trim
+operation which will take care of zeroing the device blocks. By setting
+.I zero_hugefiles
+to false, this step will always be skipped, which can be useful if it is
+known that the disk has been previously erased, or if the user programs
+that will have access to the huge files are trusted to not reveal stale
+data.
+.TP
+.I encoding
+This relation defines the file name encoding to be used if the casefold
+feature is enabled. Currently the only valid encoding is utf8-12.1 or
+utf8, which requests the most recent Unicode version; since 12.1 is the only
+available Unicode version, utf8 and utf8-12.1 have the same result.
+.I encoding_flags
+This relation defines encoding-specific flags. For utf8 encodings, the
+only available flag is strict, which will cause attempts to create file
+names containing invalid Unicode characters to be rejected by the
+kernel. Strict mode is not enabled by default.
.SH THE [devices] STANZA
Each tag in the
-.I [devices]
+.I [devices]
stanza names device name so that per-device defaults can be specified.
.TP
.I fs_type
.SH FILES
.TP
.I /etc/mke2fs.conf
-The configuration file for
+The configuration file for
.BR mke2fs (8).
.SH SEE ALSO
.BR mke2fs (8)
projects / platform / upstream / e2fsprogs.git / blobdiff