Manual: 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 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!	Oth‐
       erwise, 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 re‐
	      size2fs 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 opera‐
	      tion, 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	 in‐
	      stead.

       -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-de‐
	      vice.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 .

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 1.47.2				January 2025						RESIZE2FS(8)