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 file system is mounted, it can be used to expand the
16 size of the mounted file system, assuming the kernel and the file sys‐
17 tem supports on-line resizing. (Modern Linux 2.6 kernels will support
18 on-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 file system.
23 If no units are specified, the units of the size parameter shall be the
24 file system blocksize of the file system. Optionally, the size parame‐
25 ter may be suffixed by one of the following units designators: 'K',
26 'M', '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 file system may never be larger than the size
29 of the partition. If size parameter is not specified, it will default
30 to the size of the partition.
31 The resize2fs program does not manipulate the size of partitions. If
33 you wish to enlarge a file system, you must make sure you can expand
34 the 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 file sys‐
40 tem. After running fdisk(8), run resize2fs to resize the ext2 file
41 system to 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 file system. 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 file system!
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 file system concur‐
52 rent 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 file system size (-M) calculation
68 -f Forces resize2fs to proceed with the file system resize opera‐
70 tion, overriding some safety checks which resize2fs normally en‐
71 forces.
72 -F Flush the file system 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 Print out percentage completion bars for each resize2fs phase
80 during an offline (non-trivial) resize operation, so that the
81 user can keep track of what the program is doing. (For very
82 fast resize operations, no progress bars may be displayed.)
83 -P Print an estimate of the number of file system blocks in the
85 file system if it is shrunk using resize2fs's -M option and then
86 exit.
87 -s Turns off the 64bit feature and frees blocks that are no longer
89 in use.
90 -S RAID-stride
92 The resize2fs program will heuristically determine the RAID
93 stride that was specified when the file system was created.
94 This option allows the user to explicitly specify a RAID stride
95 setting to be used by resize2fs instead.
96 -z undo_file
98 Before overwriting a file system block, write the old contents
99 of the block to an undo file. This undo file can be used with
100 e2undo(8) to restore the old contents of the file system should
101 something go wrong. If the empty string is passed as the
102 undo_file argument, the undo file will be written to a file
103 named resize2fs-device.e2undo in the directory specified via the
104 E2FSPROGS_UNDO_DIR environment variable.
105 WARNING: The undo file cannot be used to recover from a power or
107 system crash.
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110 The minimum size of the file system as estimated by resize2fs may be
111 incorrect, especially for file systems with 1k and 2k blocksizes.
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114 resize2fs was written by Theodore Ts'o <tytso@mit.edu>.
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117 Resize2fs is Copyright 1998 by Theodore Ts'o and PowerQuest, Inc. All
118 rights reserved. As of April, 2000 Resize2fs may be redistributed un‐
119 der the terms of the GPL.
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122 fdisk(8), e2fsck(8), mke2fs(8), lvm(8), lvextend(8)
123E2fsprogs version 1.47.0 February 2023 RESIZE2FS(8)