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)