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diff --git a/misc/mke2fs.conf.5.in b/misc/mke2fs.conf.5.in new file mode 100644 index 0000000..96dbfcb --- /dev/null +++ b/misc/mke2fs.conf.5.in @@ -0,0 +1,566 @@ +.\" -*- 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 +.BR mke2fs (8) +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 +defines a relation, which assigns tags to values, or to a subsection, +which contains further relations or subsections. +.\" Tags can be assigned multiple values +An example of the INI-style format used by this configuration file +follows below: +.P + [section1] +.br + tag1 = value_a +.br + tag1 = value_b +.br + tag2 = value_c +.P + [section 2] +.br + tag3 = { +.br + subtag1 = subtag_value_a +.br + subtag1 = subtag_value_b +.br + subtag2 = subtag_value_c +.br + } +.br + tag1 = value_d +.br + tag2 = value_e +.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 +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), +and "\e\e" (for the backslash character). +.P +Some relations expect a boolean value. The parser is quite liberal on +recognizing ``yes'', '`y'', ``true'', ``t'', ``1'', ``on'', etc. as a +boolean true value, and ``no'', ``n'', ``false'', ``nil'', ``0'', +``off'' as a boolean false value. +.P +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 +.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 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. +.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 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 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 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. +.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. +.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. +.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 file system type or usage type which can be specified via the +.B \-t +or +.B \-T +options to +.BR mke2fs (8), +respectively. +.P +The +.B mke2fs +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 file system or usage types. +For +example, consider the following +.B mke2fs.conf +fragment: +.P +[defaults] +.br + base_features = sparse_super,filetype,resize_inode,dir_index +.br + blocksize = 4096 +.br + inode_size = 256 +.br + inode_ratio = 16384 +.br + +.br +[fs_types] +.br + ext3 = { +.br + features = has_journal +.br + } +.br + ext4 = { +.br + features = extents,flex_bg +.br + inode_size = 256 +.br + } +.br + small = { +.br + blocksize = 1024 +.br + inode_ratio = 4096 +.br + } +.br + floppy = { +.br + features = ^resize_inode +.br + blocksize = 1024 +.br + inode_size = 128 +.br + } +.P +If mke2fs started with a program name of +.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 +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 +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. +.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 +.I default +section: +.TP +.I base_features +This relation specifies the features which are initially enabled for this +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 +.I base_features +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 file system. The syntax is the same as the +.B -O +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. +.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 +disabled after applying the features listed in the +.I base_features +and +.I features +relations. It may be overridden by the +.B -O +command-line option to +.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 +feature is also automatically disabled since it doesn't support 64-bit +block numbers. +.TP +.I default_mntopts +This relation specifies the set of mount options which should be enabled +by default. These may be changed at a later time with the +.B -o +command-line option to +.BR tune2fs (8). +.TP +.I blocksize +This relation specifies the default blocksize if the user does not +specify a blocksize 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). +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. +.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. +.TP +.I inode_size +This relation specifies the default inode size if the user does not +specify one on the command line. +.TP +.I reserved_ratio +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 file systems with hashed b-tree directories. Valid algorithms +accepted are: +.IR legacy , +.IR half_md4 , +and +.IR tea . +.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 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. +.TP +.I options +This relation specifies additional extended options which should be +treated by +.BR mke2fs (8) +as if they were prepended to the argument of the +.B -E +option. This can be used to configure the default extended options used +by +.BR mke2fs (8) +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 file system creation. +.TP +.I cluster_size +This relation specifies the default cluster size if the bigalloc file +system feature is enabled. It can be overridden via the +.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] +stanza names device name so that per-device defaults can be specified. +.TP +.I fs_type +This relation specifies the default parameter for the +.B \-t +option, if this option isn't specified on the command line. +.TP +.I usage_types +This relation specifies the default parameter for the +.B \-T +option, if this option isn't specified on the command line. +.SH FILES +.TP +.I /etc/mke2fs.conf +The configuration file for +.BR mke2fs (8). +.SH SEE ALSO +.BR mke2fs (8) |