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 sys-
tem 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 fea-
ture 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 parame-
ter 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 respec-
tively. 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 oper-
ation will certainly not work, and you may lose your entire file sys-
tem. 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, respec-
tively. 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 concur-
rent 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 opera-
tion, overriding some safety checks which resize2fs normally en-
forces.
-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 un-
der the terms of the GPL.
SEE ALSO
fdisk(8), e2fsck(8), mke2fs(8), lvm(8), lvextend(8)
E2fsprogs version 1.47.0 February 2023 RESIZE2FS(8)
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