NAME

       resize2fs - ext2/ext3/ext4 file system resizer

SYNOPSIS

       resize2fs  [  -fFpPMbs  ]  [ -d debug-flags ] [ -S RAID-stride ] [ -z undo_file ] device [
       size ]

DESCRIPTION

       The resize2fs program will resize ext2, ext3, or ext4 file systems.  It  can  be  used  to
       enlarge  or  shrink  an  unmounted  file  system  located on device.  If the filesystem is
       mounted, it can be used to expand the size of the mounted filesystem, assuming the  kernel
       and the file system supports on-line resizing.  (Modern Linux 2.6 kernels will support on-
       line resize for file systems mounted using ext3 and ext4; ext3 file systems  will  require
       the use of file systems with the resize_inode feature enabled.)

       The  size  parameter  specifies the requested new size of the filesystem.  If no units are
       specified, the units of the size parameter  shall  be  the  filesystem  blocksize  of  the
       filesystem.   Optionally, the size parameter may be suffixed by one of the following units
       designators: 'K', 'M', 'G', 'T' (either upper-case or lower-case) or 's' for  power-of-two
       kilobytes,  megabytes,  gigabytes, terabytes or 512 byte sectors respectively. The size of
       the filesystem may never be larger than the size of the partition.  If size  parameter  is
       not specified, it will default to the size of the partition.

       The  resize2fs program does not manipulate the size of partitions.  If you wish to enlarge
       a filesystem, you must make sure you can expand  the  size  of  the  underlying  partition
       first.  This can be done using fdisk(8) by deleting the partition and recreating it with a
       larger size or using lvextend(8), if you're using the logical volume manager lvm(8).  When
       recreating  the partition, make sure you create it with the same starting disk cylinder as
       before!  Otherwise, the resize operation will certainly not work, and you  may  lose  your
       entire filesystem.  After running fdisk(8), run resize2fs to resize the ext2 filesystem to
       use all of the space in the newly enlarged partition.

       If you wish to shrink an ext2 partition,  first  use  resize2fs  to  shrink  the  size  of
       filesystem.   Then  you  may  use  fdisk(8)  to  shrink  the  size of the partition.  When
       shrinking the size of the partition, make sure you do not make it  smaller  than  the  new
       size of the ext2 filesystem!

       The  -b  and -s options enable and disable the 64bit feature, respectively.  The resize2fs
       program will, of course, take care of resizing the  block  group  descriptors  and  moving
       other  data blocks out of the way, as needed.  It is not possible to resize the filesystem
       concurrent with changing the 64bit status.

OPTIONS

       -b     Turns on the 64bit feature, resizes the group descriptors as necessary,  and  moves
              other metadata out of the way.

       -d debug-flags
              Turns  on various resize2fs debugging features, if they have been compiled into the
              binary.  debug-flags should be computed  by  adding  the  numbers  of  the  desired
              features from the following list:
                   2    - Debug block relocations
                   4    - Debug inode relocations
                   8    - Debug moving the inode table
                   16   - Print timing information
                   32   - Debug minimum filesystem size (-M) calculation

       -f     Forces  resize2fs  to proceed with the filesystem resize operation, overriding some
              safety checks which resize2fs normally enforces.

       -F     Flush the filesystem device's buffer caches before beginning.  Only  really  useful
              for doing resize2fs time trials.

       -M     Shrink  the  file  system to minimize its size as much as possible, given the files
              stored in the file system.

       -p     Prints out a percentage completion bars for  each  resize2fs  operation  during  an
              offline resize, so that the user can keep track of what the program is doing.

       -P     Print  an  estimate of the number of file system blocks in the file system if it is
              shrunk using resize2fs's -M option and then exit.

       -s     Turns off the 64bit feature and frees blocks that are no longer in use.

       -S RAID-stride
              The resize2fs program  will  heuristically  determine  the  RAID  stride  that  was
              specified  when  the  filesystem  was  created.   This  option  allows  the user to
              explicitly specify a RAID stride setting to be used by resize2fs instead.

       -z undo_file
              Before overwriting a file system block, write the old contents of the block  to  an
              undo  file.   This undo file can be used with e2undo(8) to restore the old contents
              of the file system should something go wrong.  If the empty string is passed as the
              undo_file  argument,  the  undo  file  will  be  written to a file named resize2fs-
              device.e2undo in the directory specified  via  the  E2FSPROGS_UNDO_DIR  environment
              variable.

              WARNING: The undo file cannot be used to recover from a power or system crash.

KNOWN BUGS

       The  minimum size of the filesystem as estimated by resize2fs may be incorrect, especially
       for filesystems with 1k and 2k blocksizes.

AUTHOR

       resize2fs was written by Theodore Ts'o <tytso@mit.edu>.

COPYRIGHT

       Resize2fs is Copyright 1998 by Theodore Ts'o and PowerQuest, Inc.   All  rights  reserved.
       As of April, 2000 Resize2fs may be redistributed under the terms of the GPL.

SEE ALSO

       fdisk(8), e2fsck(8), mke2fs(8), lvm(8), lvextend(8)