Ubuntu Manpage: resize2fs - ext2/ext3/ext4 file system resizer

Provided by: e2fsprogs_1.42.13-1ubuntu1.2_amd64

NAME

       resize2fs - ext2/ext3/ext4 file system resizer

SYNOPSIS

       resize2fs [ -fFpPM ] [ -d debug-flags ] [ -S RAID-stride ] 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 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 the
partition.

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 filesystem!

OPTIONS

       -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 filesystem size (-M) calculation

       -f     Forces  resize2fs  to proceed with the filesystem resize operation, overriding some
              safety checks which resize2fs normally enforces.

       -F     Flush the filesystem device's buffer caches before beginning.  Only  really  useful
              for doing resize2fs time trials.

       -M     Shrink the filesystem to the minimum size.

       -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 the minimum size of the filesystem and exit.

       -S RAID-stride
              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.

KNOWN BUGS

       The minimum size of the filesystem as estimated by resize2fs may be incorrect,  especially
       for filesystems 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 under the terms of the GPL.