1RESIZE2FS(8) System Manager's Manual RESIZE2FS(8)
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6 resize2fs - ext2/ext3/ext4 file system resizer
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9 resize2fs [ -fFpPMbs ] [ -d debug-flags ] [ -S RAID-stride ] [ -z
10 undo_file ] device [ size ]
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13 The resize2fs program will resize ext2, ext3, or ext4 file systems. It
14 can be used to enlarge or shrink an unmounted file system located on
15 device. If the filesystem is mounted, it can be used to expand the
16 size of the mounted filesystem, assuming the kernel and the file system
17 supports on-line resizing. (Modern Linux 2.6 kernels will support on-
18 line resize for file systems mounted using ext3 and ext4; ext3 file
19 systems will require the use of file systems with the resize_inode fea‐
20 ture enabled.)
21 The size parameter specifies the requested new size of the filesystem.
23 If no units are specified, the units of the size parameter shall be the
24 filesystem blocksize of the filesystem. Optionally, the size parameter
25 may be suffixed by one of the following units designators: 'K', 'M',
26 'G', 'T' (either upper-case or lower-case) or 's' for power-of-two
27 kilobytes, megabytes, gigabytes, terabytes or 512 byte sectors respec‐
28 tively. The size of the filesystem may never be larger than the size of
29 the partition. If size parameter is not specified, it will default to
30 the size of the partition.
31 The resize2fs program does not manipulate the size of partitions. If
33 you wish to enlarge a filesystem, you must make sure you can expand the
34 size of the underlying partition first. This can be done using
35 fdisk(8) by deleting the partition and recreating it with a larger size
36 or using lvextend(8), if you're using the logical volume manager
37 lvm(8). When recreating the partition, make sure you create it with
38 the same starting disk cylinder as before! Otherwise, the resize oper‐
39 ation will certainly not work, and you may lose your entire filesystem.
40 After running fdisk(8), run resize2fs to resize the ext2 filesystem to
41 use all of the space in the newly enlarged partition.
42 If you wish to shrink an ext2 partition, first use resize2fs to shrink
44 the size of filesystem. Then you may use fdisk(8) to shrink the size
45 of the partition. When shrinking the size of the partition, make sure
46 you do not make it smaller than the new size of the ext2 filesystem!
47 The -b and -s options enable and disable the 64bit feature, respec‐
49 tively. The resize2fs program will, of course, take care of resizing
50 the block group descriptors and moving other data blocks out of the
51 way, as needed. It is not possible to resize the filesystem concurrent
52 with changing the 64bit status.
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55 -b Turns on the 64bit feature, resizes the group descriptors as
56 necessary, and moves other metadata out of the way.
57 -d debug-flags
59 Turns on various resize2fs debugging features, if they have been
60 compiled into the binary. debug-flags should be computed by
61 adding the numbers of the desired features from the following
62 list:
63 2 - Debug block relocations
64 4 - Debug inode relocations
65 8 - Debug moving the inode table
66 16 - Print timing information
67 32 - Debug minimum filesystem size (-M) calculation
68 -f Forces resize2fs to proceed with the filesystem resize opera‐
70 tion, overriding some safety checks which resize2fs normally en‐
71 forces.
72 -F Flush the filesystem device's buffer caches before beginning.
74 Only really useful for doing resize2fs time trials.
75 -M Shrink the file system to minimize its size as much as possible,
77 given the files stored in the file system.
78 -p Prints out a percentage completion bars for each resize2fs oper‐
80 ation during an offline resize, so that the user can keep track
81 of what the program is doing.
82 -P Print an estimate of the number of file system blocks in the
84 file system if it is shrunk using resize2fs's -M option and then
85 exit.
86 -s Turns off the 64bit feature and frees blocks that are no longer
88 in use.
89 -S RAID-stride
91 The resize2fs program will heuristically determine the RAID
92 stride that was specified when the filesystem was created. This
93 option allows the user to explicitly specify a RAID stride set‐
94 ting to be used by resize2fs instead.
95 -z undo_file
97 Before overwriting a file system block, write the old contents
98 of the block to an undo file. This undo file can be used with
99 e2undo(8) to restore the old contents of the file system should
100 something go wrong. If the empty string is passed as the
101 undo_file argument, the undo file will be written to a file
102 named resize2fs-device.e2undo in the directory specified via the
103 E2FSPROGS_UNDO_DIR environment variable.
104 WARNING: The undo file cannot be used to recover from a power or
106 system crash.
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109 The minimum size of the filesystem as estimated by resize2fs may be in‐
110 correct, especially for filesystems with 1k and 2k blocksizes.
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113 resize2fs was written by Theodore Ts'o <tytso@mit.edu>.
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116 Resize2fs is Copyright 1998 by Theodore Ts'o and PowerQuest, Inc. All
117 rights reserved. As of April, 2000 Resize2fs may be redistributed un‐
118 der the terms of the GPL.
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121 fdisk(8), e2fsck(8), mke2fs(8), lvm(8), lvextend(8)
122E2fsprogs version 1.46.3 July 2021 RESIZE2FS(8)