*nix Documentation Project
·  Home
 +   man pages
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

  man pages->Linux man pages -> mke2fs (8)              



NAME    [Toc]    [Back]

       mke2fs - create a Linux second extended file system

SYNOPSIS    [Toc]    [Back]

       mke2fs [ -c | -l filename ] [ -b block-size ] [ -f fragment-size ] [ -i
       bytes-per-inode ] [ -j ] [ -J journal-options ] [ -N number-of-inodes ]
       [  -n  ]  [ -m reserved-blocks-percentage ] [ -o creator-os ] [ -O fea-
       ture[,...]  ] [ -q ] [ -r fs-revision-level ] [ -R raid-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 ]

DESCRIPTION    [Toc]    [Back]

       mke2fs  is  used  to  create  a	Linux second extended file system on a
       device (usually 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 specified.

OPTIONS    [Toc]    [Back]

       -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 blocksize
 is determined by the file  system  size  and  the  expected
	      usage of the filesystem (see the -T option).

       -c     Check the device for bad blocks before creating the file system.
	      If this option is specified twice, then a  slower,  destructive,
	      read-write test is used instead of a fast read-only test.

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

       -F     Force mke2fs to run, even if the specified device is not a block
	      special device, or appears to be mounted.

       -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 shouldn't 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  correct
 value for this parameter.

       -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  commandline.
   Journal  options	are  comma  separated, and may take an
	      argument using the equals ('=')  sign.   The  following  journal
	      options are supported:

			  Create  a  journal  stored in 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.
			  The  journal	must  fit  within  the	newly  created

			  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.

			  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 device's 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 automatically
  pass the correct parameters to the badblocks program.

       -L     Set the volume label for the filesystem.

       -m reserved-blocks-percentage
	      Specify the percentage of the filesystem blocks reserved for the
	      super-user.  This value defaults to 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 filesytem should be

       -n     causes mke2fs to not actually create a filesystem,  but  display
	      what it would do if it were to create a filesystem.

       -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).
	      Currently,  the sparse_super and filetype features are turned on
	      by default unless mke2fs is run on a system with a pre-2.2 Linux
	      kernel.  Filesystems that may need to mounted on pre-2.2 kernels
	      should be created with -O none (or -r 0 for 1.2  kernels)  which
	      will  disable  these features, even if mke2fs is run on a system
	      which can support them.

	      The following filesystem options are supported:

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

			  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.

       -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.

       -R raid-options
	      Set  raid-related  options for the filesystem.  Raid options are
	      comma separated, and may take an argument using the equals ('=')
	      sign.  The following options are supported:

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

       -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  salvageable.
   It  is critical to specify the correct filesystem blocksize
 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 chose optimal filesystem parameters for that use.  The  supported
 filesystem types are:

		   news        one inode per 4kb block

		   largefile   one inode per megabyte

		   largefile4  one inode per 4 megabytes

       -v     Verbose execution.

       -V     Print the version number of mke2fs and exit.

AUTHOR    [Toc]    [Back]

       This   version	of   mke2fs   has   been   written  by	Theodore  Ts'o

BUGS    [Toc]    [Back]

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

AVAILABILITY    [Toc]    [Back]

       mke2fs  is  part  of  the  e2fsprogs  package  and  is  available  from

SEE ALSO    [Toc]    [Back]

       badblocks(8), dumpe2fs(8), e2fsck(8), tune2fs(8)

E2fsprogs version 1.27		  March 2002			     MKE2FS(8)
[ Back ]
 Similar pages
Name OS Title
mklost+found Linux create a lost+found directory on a mounted Linux second extended file system
fsck.ext2 Linux check a Linux second extended file system
fsck.ext3 Linux check a Linux second extended file system
e2fsck Linux check a Linux second extended file system
chattr Linux change file attributes on a Linux second extended file system
lsattr Linux list file attributes on a Linux second extended file system
mkdosfs Linux create an MS-DOS file system under Linux
linprocfs FreeBSD Linux process file system
mkfs Linux build a Linux file system
fsck Linux check and repair a Linux file system
Copyright © 2004-2005 DeniX Solutions SRL
newsletter delivery service