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 ] [ -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 run, even if the specified device is not a block
              special device, or appears to be mounted.

       -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 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.   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 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 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  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

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

E2fsprogs version 1.39             May 2006                          MKE2FS(8)