MKE2FS(8)                                                            MKE2FS(8)

       mke2fs - create an ext2/3 filesystem

       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 ]

       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 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  cor-
              rect 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  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.

                          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 auto-
              matically 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.  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).
              Features which are normally turned on by default may be disabled
              by  prefixing the feature with a caret ('^') symbol.  Currently,
              the sparse_super and filetype features are turned on by  default
              when  mke2fs  is run on a system with Linux 2.2 or later (unless
              creator-os is set to the Hurd).  Filesystems that may need to be
              mounted on pre-2.2 Linux or other kernels should be created with
              -O none (or -r 0 for Linux 1.2) which will  disable  these  fea-
              tures, 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  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 chose optimal filesystem parameters for that use.  The  sup-
              ported 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.

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

       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

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

E2fsprogs version 1.32           November 2002                       MKE2FS(8)