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 filesystem is mounted, it can be used to expand
the size of the mounted filesystem, 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
filesystem. If no units are specified, the units of the size
parameter shall be the filesystem blocksize of the filesystem.
Optionally, the size parameter may be suffixed by one of the
following the units designators: 's', 'K', 'M', or 'G', for 512 byte
sectors, kilobytes, megabytes, or gigabytes, respectively. The size
of the filesystem may never be larger than the size of the partition.
If size parameter is not specified, it will default to the size of
Note: when kilobytes is used above, I mean real, power-of-2
kilobytes, (i.e., 1024 bytes), which some politically correct folks
insist should be the stupid-sounding ``kibibytes''. The same holds
true for megabytes, also sometimes known as ``mebibytes'', or
gigabytes, as the amazingly silly ``gibibytes''. Makes you want to
gibber, doesn't it?
The resize2fs program does not manipulate the size of partitions. If
you wish to enlarge a filesystem, 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
filesystem. After running fdisk(8), run resize2fs to resize the ext2
filesystem 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 filesystem. 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
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 filesystem
concurrent with changing the 64bit status.
-b Turns on the 64bit feature, resizes the group descriptors as
necessary, and moves other metadata out of the way.
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
2 - Debug block relocations
4 - Debug inode relocations
8 - Debug moving the inode table
16 - Print timing information
32 - Debug minimum filesystem size (-M) calculation
-f Forces resize2fs to proceed with the filesystem resize
operation, overriding some safety checks which resize2fs
-F Flush the filesystem 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 Prints out a percentage completion bars for each resize2fs
operation during an offline resize, so that the user can keep
track of what the program is doing.
-P Print an extimate of the number of file system blocks in the
file system if it is shrunk using resize2fs's -M option and
-s Turns off the 64bit feature and frees blocks that are no
longer in use.
The resize2fs program will heuristically determine the RAID
stride that was specified when the filesystem was created.
This option allows the user to explicitly specify a RAID
stride setting to be used by resize2fs instead.
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.
This page is part of the e2fsprogs (utilities for ext2/3/4
filesystems) project. Information about the project can be found at
⟨http://e2fsprogs.sourceforge.net/⟩. It is not known how to report
bugs for this man page; if you know, please send a mail to
firstname.lastname@example.org. This page was obtained from the project's
upstream Git repository
⟨git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git⟩ on 2017-03-13.
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
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E2fsprogs version 1.43.5-WIP February 2017 RESIZE2FS(8)