resize2fs - ext2/ext3/ext4 file system resizer
resize2fs [
-fFpPMbs ] [
-d debug-flags ] [
-S RAID-stride ] [
-z undo_file ]
device [
size ]
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.
- -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.
The minimum size of the file system as estimated by resize2fs may be incorrect,
especially for file systems with 1k and 2k blocksizes.
resize2fs was written by Theodore Ts'o <
[email protected]>.
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.
fdisk(8),
e2fsck(8),
mke2fs(8),
lvm(8),
lvextend(8)