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MKE2FS(8)							     MKE2FS(8)

       mke2fs - create an ext2/ext3 filesystem

       mke2fs [ -c | -l filename ] [ -b block-size ] [ -f fragment-size ] [ -g
       blocks-per-group ] [ -i bytes-per-inode ] [ -I inode-size ] [ -j ] [ -J
       journal-options	] [ -N number-of-inodes ] [ -n ] [ -m reserved-blocks-
       percentage ] [ -o creator-os ] [ -O feature[,...]  ] [ -q ]  [  -r  fs-
       revision-level  ]  [  -E  extended-options ] [ -v ] [ -F ] [ -L volume-
       label ] [ -M last-mounted-directory ] [ -S ] [ -T filesystem-type  ]  [
       -V ] device [ blocks-count ]

       mke2fs -O journal_dev [ -b block-size ] [ -L volume-label ] [ -n ] [ -q
       ] [ -v ] external-journal [ blocks-count ]

       mke2fs is used to create an ext2/ext3 filesystem  (usually  in  a  disk
       partition).   device  is  the  special file corresponding to the device
       (e.g /dev/hdXX).  blocks-count is the number of blocks on  the  device.
       If  omitted,  mke2fs  automagically  figures  the file system size.  If
       called as mkfs.ext3 a journal is created as if the -j option was speci

       -b block-size
	      Specify the size of blocks in bytes.  Valid block size vales are
	      1024, 2048 and 4096 bytes per block.  If omitted, mke2fs	block-
	      size is heuristically determined by the file system size and the
	      expected usage of the filesystem (see the -T option).  If block-
	      size  is	negative, then mke2fs will use heuristics to determine
	      the appropriate block size, with the constraint that  the  block
	      size will be at least block-size bytes.  This is useful for cer
	      tain hardware devices which require that the blocksize be a mul
	      tiple of 2k.

       -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.

       -E extended-options
	      Set  extended  options for the filesystem.  Extended options are
	      comma separated, and may take an argument using the equals (=)
	      sign.   The  -E  option  used  to  be  -R in earlier versions of
	      mke2fs.  The -R option is still accepted for backwards  compati
	      bility.	The following extended options are supported:

			  Configure  the  filesystem  for  a  RAID  array with
			  stripe-size filesystem blocks per stripe.

			  Reserve  enough  space  so  that  the  block	 group
			  descriptor  table  can  grow to support a filesystem
			  that has max-online-resize blocks.

       -f fragment-size
	      Specify the size of fragments in bytes.

       -F     Force mke2fs to create  a  filesystem,  even  if	the  specified
	      device is not a partition on a block special device, or if other
	      parameters do not make sense.  In order to force mke2fs to  cre
	      ate  a filesystem even if the filesystem appears to be in use or
	      is mounted (a truly dangerous thing to do), this option must  be
	      specified twice.

       -g blocks-per-group
	      Specify  the number of blocks in a block group.  There is gener
	      ally no reason the user to  ever	set  this  parameter,  as  the
	      default  is optimal for the filesystem.  (For administrators who
	      are creating filesystems on RAID arrays, it is preferable to use
	      the  stride  RAID parameter as part of the -R option rather than
	      manipulating the number of blocks per group.)   This  option  is
	      generally used by developers who are developing test cases.

       -i bytes-per-inode
	      Specify  the  bytes/inode  ratio.   mke2fs  creates an inode for
	      every bytes-per-inode bytes of space on the  disk.   The	larger
	      the  bytes-per-inode  ratio,  the  fewer inodes will be created.
	      This value generally shouldnt be smaller than the blocksize  of
	      the  filesystem,	since  then  too many inodes will be made.  Be
	      warned that is not possible to expand the number of inodes on  a
	      filesystem  after it is created, so be careful deciding the cor
	      rect value for this parameter.

       -I inode-size
	      Specify the  size  of  each  inode  in  bytes.   mke2fs  creates
	      128-byte	inodes	by  default.  In kernels after 2.6.10 and some
	      earlier vendor kernels it is possible to utilize	larger	inodes
	      to  store  extended  attributes  for  improved performance.  The
	      inode-size value must be a power of two larger or equal to  128.
	      The  larger  the	inode-size the more space the inode table will
	      consume, and this reduces the usable space in the filesystem and
	      can also negatively impact performance.  Using the default value
	      is always safe, though it  may  be  desirable  to  use  256-byte
	      inodes   if  full  backward  compatibility  is  not  a  concern.
	      Extended attributes stored in large inodes are not visible  with
	      older  kernels,  and such filesystems will not be mountable with
	      2.4 kernels at all.  It is not possible  to  change  this  value
	      after the filesystem is created.

       -j     Create the filesystem with an ext3 journal.  If the -J option is
	      not specified, the default journal parameters will  be  used  to
	      create  an  appropriately  sized	journal (given the size of the
	      filesystem) stored within the filesystem.  Note that you must be
	      using  a kernel which has ext3 support in order to actually make
	      use of the journal.

       -J journal-options
	      Create the ext3 journal using options specified on the  command-
	      line.   Journal  options	are  comma  separated, and may take an
	      argument using the equals (=)  sign.   The  following  journal
	      options are supported:

			  Create  an internal journal (i.e., stored inside the
			  filesystem) of  size	journal-size  megabytes.   The
			  size of the journal must be at least 1024 filesystem
			  blocks (i.e., 1MB if using 1k blocks, 4MB  if  using
			  4k  blocks,  etc.)   and may be no more than 102,400
			  filesystem blocks.

			  Attach the filesystem to the	journal  block	device
			  located  on  external-journal.  The external journal
			  must already have been created using the command

			  mke2fs -O journal_dev external-journal

			  Note that external-journal must  have  been  created
			  with	the same block size as the new filesystem.  In
			  addition, while there is support for attaching  mul
			  tiple  filesystems to a single external journal, the
			  Linux kernel and e2fsck(8) do not currently  support
			  shared external journals yet.

			  Instead of specifying a device name directly, exter
			  nal-journal  can  also  be   specified   by	either
			  LABEL=label  or  UUID=UUID  to  locate  the external
			  journal by either the volume label or UUID stored in
			  the  ext2  superblock  at  the start of the journal.
			  Use dumpe2fs(8) to display a journal devices volume
			  label   and	UUID.	See  also  the	-L  option  of

	      Only one of the size or  device  options	can  be  given	for  a

       -l filename
	      Read  the  bad  blocks  list from filename.  Note that the block
	      numbers in the bad block list must be generated using  the  same
	      block  size  as  used  by mke2fs.  As a result, the -c option to
	      mke2fs is a much simpler and less error-prone method of checking
	      a disk for bad blocks before formatting it, as mke2fs will auto
	      matically pass the correct parameters to the badblocks  program.

       -L new-volume-label
	      Set  the	volume	label  for the filesystem to new-volume-label.
	      The maximum length of the volume label is 16 bytes.

       -m reserved-blocks-percentage
	      Specify the percentage of the filesystem blocks reserved for the
	      super-user.   This  avoids  fragmentation, and allows root-owned
	      daemons, such as syslogd(8), to continue to  function  correctly
	      after non-privileged processes are prevented from writing to the
	      filesystem.  The default percentage is 5%.

       -M     Set the last mounted directory for the filesystem.   This  might
	      be  useful  for  the  sake of utilities that key off of the last
	      mounted directory to determine where the	filesystem  should  be

       -n     causes  mke2fs  to not actually create a filesystem, but display
	      what it would do if it were to create a filesystem.  This can be
	      used  to	determine the location of the backup superblocks for a
	      particular filesystem, so long as  the  mke2fs  parameters  that
	      were  passed when the filesystem was originally created are used
	      again.  (With the -n option added, of course!)

       -N number-of-inodes
	      overrides the default calculation of the number of  inodes  that
	      should  be  reserved  for  the filesystem (which is based on the
	      number of blocks and the bytes-per-inode	ratio).   This	allows
	      the user to specify the number of desired inodes directly.

       -o creator-os
	      Manually override the default value of the "creator os" field of
	      the filesystem.  Normally the creator field is set by default to
	      the native OS of the mke2fs executable.

       -O feature[,...]
	      Create  filesystem  with	given  features  (filesystem options),
	      overriding the default filesystem options.  The default features
	      which  are enabled by default are specified by the base_features
	      relation,  either  in   the   [libdefaults]   section   in   the
	      /etc/mke2fs.conf configuration file, or in the subsection of the
	      [fs_types] section for the filesystem type as specified  by  the
	      -T  option.   The filesystem type-specific configuration setting
	      found in the [fs_types] section will override the global default
	      found in [libdefaults].

	      The  filesystem  feature set will be further edited using either
	      the feature set specification specified by this  option,	or  if
	      this  option  is not specified, by the default_features relation
	      for the filesystem type being created, or in  the  [libdefaults]
	      section of the configuration file.

	      The  filesystem  feature set is comprised of a list of features,
	      separated by commas, that are to be enabled.  To disable a  fea
	      ture, simply prefix the feature name with a  caret (^) charac
	      ter.   The  pseudo-filesystem  feature  "none"  will  clear  all
	      filesystem features.

			  Use  hashed  b-trees	to  speed  up lookups in large

			  Store file type information in directory entries.

			  Create an ext3 journal (as if using the -j  option).

			  Create  an external ext3 journal on the given device
			  instead of a regular	ext2  filesystem.   Note  that
			  external-journal must be created with the same block
			  size as the filesystems that will be using it.

			  Reserve space so the block  group  descriptor  table
			  may  grow in the future.  Useful for online resizing
			  using resize2fs.  By default mke2fs will attempt  to
			  reserve enough space so that the filesystem may grow
			  to 1024 times its initial size.  This can be changed
			  using resize extended option.

			  Create  a  filesystem  with  fewer superblock backup
			  copies (saves space on large filesystems).

       -q     Quiet execution.	Useful if mke2fs is run in a script.

       -r revision
	      Set the filesystem revision for the new filesystem.   Note  that
	      1.2 kernels only support revision 0 filesystems.	The default is
	      to create revision 1 filesystems.

       -S     Write superblock and group descriptors only.  This is useful  if
	      all  of the superblock and backup superblocks are corrupted, and
	      a last-ditch recovery method is desired.	It  causes  mke2fs  to
	      reinitialize  the  superblock  and  group descriptors, while not
	      touching the inode table and the block and inode	bitmaps.   The
	      e2fsck  program  should  be run immediately after this option is
	      used, and there is no guarantee that any data will  be  salvage
	      able.   It  is critical to specify the correct filesystem block
	      size when using this option, or there is no chance of  recovery.

       -T fs-type
	      Specify  how  the filesystem is going to be used, so that mke2fs
	      can choose optimal filesystem  parameters  for  that  use.   The
	      filesystem  types  that  are can be supported are defined in the
	      configuration file /etc/mke2fs.conf(5).  The default  configura
	      tion  file contains definitions for the filesystem types: small,
	      floppy, news, largefile, and largefile4.

       -v     Verbose execution.

       -V     Print the version number of mke2fs and exit.

       This  version  of  mke2fs   has	 been	written   by   Theodore   Tso

       mke2fs  accepts the -f option but currently ignores it because the sec
       ond extended file system does not support fragments yet.
       There may be other ones.  Please, report them to the author.

       mke2fs  is  part  of  the  e2fsprogs  package  and  is  available  from

       mke2fs.conf(5), badblocks(8), dumpe2fs(8), e2fsck(8), tune2fs(8)

E2fsprogs version 1.40-WIP	 November 2006			     MKE2FS(8)

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