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 file system is mounted, it can
       be used to expand the size of the mounted file system, 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

       The size parameter specifies the requested new size of the file
       system.  If no units are specified, the units of the size
       parameter shall be the file system blocksize of the file system.
       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 file system 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 file system, 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 file system.  After running
       fdisk(8), run resize2fs to resize the ext2 file system 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 file system.  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 file system!

       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 file system 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 file system size (-M)

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

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

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

       -p     Print out percentage completion bars for each resize2fs
              phase during an offline (non-trivial) resize operation, so
              that the user can keep track of what the program is doing.
              (For very fast resize operations, no progress bars may be

       -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 file system was
              created.  This option allows the user to explicitly
              specify a RAID stride setting to be used by resize2fs

       -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 file system as estimated by resize2fs may
       be incorrect, especially for file systems with 1k and 2k

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 ⟨⟩.  It is not known how to
       report bugs for this man page; if you know, please send a mail to  This page was obtained from the project's
       upstream Git repository
       ⟨git://⟩ on
       2024-06-14.  (At that time, the date of the most recent commit
       that was found in the repository was 2024-05-20.)  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to

E2fsprogs version 1.47.1        May 2024                    RESIZE2FS(8)

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