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 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 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 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
       -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) calculation

       -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 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)

E2fsprogs version 1.47.3	   July 2025			  RESIZE2FS(8)