RESIZE2FS(8)              (August 2021)              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 file system is
          mounted, it can be used to expand the size of the mounted
          file system, assuming the kernel and the file system sup-
          ports on-line resizing.  (Modern Linux 2.6 kernels will sup-
          port 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
          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 parti-
          tion.

          The resize2fs program does not manipulate the size of parti-
          tions.  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 par-
          tition 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!  Other-
          wise, 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 shrink-
          ing 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,

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          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 pos-
          sible to resize the file system concurrent with changing the
          64bit status.

     OPTIONS
          -b   Turns on the 64bit feature, resizes the group descrip-
               tors 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 fea-
               tures 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) calcu-
               lation

          -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
               trials.

          -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 displayed.)

          -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

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               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 file system as estimated by
          resize2fs may be incorrect, especially for file systems 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)

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