ext2resize(8)

NAME

ext2resize - GNU ext2 filesystem resizer

SYNOPSIS

ext2resize  [-d]  [-f]  [  -q]  [-u]  [-v]   [-V]   device
[size[b|K|M|G|T]]

DESCRIPTION

The ext2resize tool resizes an unmounted ext2 or ext3 file

system. It enlarges or shrinks the file system located on device

(partition, loop device, logical volume, ...) so that it will

have size ext2 filesystem blocks. If the size parameter is not

specified, the filesystem will be resized to fill the given de

vice. The size parameter may have one of the optional modifiers

b, K, M, G, or T which means the size parameter is given in

512-byte blocks, kilo-, mega-, giga-, or terabytes respectively.

The ext2resize program does not manipulate the size of the

device. If you wish to enlarge a filesystem, you must make sure

you expand the underlying device first. This can be done using

fdisk(8) for partitions, by deleting the partition and recreating

it with a larger size (assuming there is free space after the

partition in question). Make sure you re-create it with the same

starting disk cylinder as before! Otherwise, the resize opera

tion will certainly not work, and you may lose your entire

filesystem. Logical Volumes can be extended with lvextend(8)

prior to growing a filesystem, or after shrinking it. Alternate

ly, the e2fsadm(8) tool can be used to combine the operations of

resizing the Logical Volume and the filesystem into one step.

If you wish to shrink an ext2 or ext3 partition, first use

ext2resize to shrink the file system. You may then use fdisk(8)

or lvreduce(8) to shrink the device. When shrinking the size of

the device, make sure you do not make it smaller than the reduced

size of the ext2 filesystem. If you are not sure of the exact

device size, shrink the filesystem slightly more than desired,

shrink the device, and then run ext2resize again to increase the

filesystem to fill the new device size.

-d, --debug

Turns on various debugging messages, normally only

useful if you are working on a problem.

-f, --force

Force, do not perform sanity checks. Use with EX

TREME care, you are on your own.

-u, --unsafe

Do not flush the device's buffer cache during the

resize operation.

-q, --quiet

Do not print anything but error messages.

-v, --verbose

Turn on extra progress status messages.

-V, --version

Print the version number and exit.

RETURN VALUES

0 Resizing successful.

1 Error in command line.

2 Error during resize operation.

EXAMPLES

The following example shows how to test ext2resize on a

loop device. First a file of 10MB is created which is mounted on

the loop device. Then an 5MB ext2 filesystem is created on the

loop device, after mounting its size is verified. Before extend

ing unmounting is necessary, when the size parameter is not spec

ified the filesystem is extended to fill the loop device.

dd if=/dev/zero of=/tmp/file bs=1k count=10240
losetup /dev/loop0 /tmp/file
mke2fs /dev/loop0 5120
mkdir /mnt/test
mount /dev/loop0 /mnt/test
df /mnt/test
umount /mnt/test
ext2resize /dev/loop0
mount /dev/loop0 /mnt/test
df /mnt/test

For shrinking the loop device we need to unmount it first,

then run ext2resize with a size parameter, in this case 8MB.

umount /mnt/test
ext2resize /dev/loop0 8M
mount /mnt/test
df /mnt/test

WARNING

Note that resizing a filesystem is inherently dangerous

and may corrupt filesystems, although no errors resulting in data

loss have ever been reported to the author. Use with caution.

Backups are always a good idea, because your disk may fail at any

time, you delete files by accident, or your computer is struck by

a meteor.

AUTHOR

GNU ext2resize was written by Lennert Buytenhek

<buytenh@gnu.org> with the help of volunteers around the net.

This man page was originally written by Joey Hess

<joey@kitenet.net>, and Dirk de Rycke significantly improved that

version.

COPYRIGHT

GNU ext2resize is (C) Copyright 1998, 1999 by Lennert

Buytenhek, and 2000, 2001 Andreas Dilger, and may be distributed

under the terms of the GNU General Public License.

SEE ALSO

fdisk(8) e2fsck(8) e2fsadm(8) mke2fs(8) losetup(8)

lvextend(8) lvreduce(8)

ext2resize v1.1.18 July 2002

EXT2RESIZE(8)