resize2fs

RESIZE2FS(8)                System Manager's Manual               RESIZE2FS(8)

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 fea-
       ture 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  respec-
       tively. 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 oper-
       ation 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, respec-
       tively.  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 opera-
              tion, overriding some safety checks which resize2fs normally en-
              forces.

       -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 oper-
              ation 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  set-
              ting 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 in-
       correct, 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  un-
       der the terms of the GPL.

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

E2fsprogs version 1.45.5         January 2020                     RESIZE2FS(8)