resize2fs(8) — Linux manual page


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

NAME         top

       resize2fs - ext2/ext3/ext4 file system resizer

SYNOPSIS         top

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

DESCRIPTION         top

       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

       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

       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         top

       -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         top

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

AUTHOR         top

       resize2fs was written by Theodore Ts'o <>.

COPYRIGHT         top

       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         top

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

COLOPHON         top

       This page is part of the e2fsprogs (utilities for ext2/3/4
       filesystems) project.  Information about the project can be found at
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       ⟨git://⟩ on 2020-11-01.
       (At that time, the date of the most recent commit that was found in
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E2fsprogs version 1.46-WIP       March 2020                     RESIZE2FS(8)

Pages that refer to this page: ext2(5)ext3(5)ext4(5)fsadm(8)