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review.blissroms.org / platform_external_e2fsprogs / refs/heads/n-mr2 / . / misc / e2freefrag.8.in
blob: 564be741224d6f0b283906a74f5bb8f18bd65ecb [file] [log] [blame]
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]1.\" -*- nroff -*-
Theodore Ts'offd80782009-08-22 23:41:49 -0400[diff] [blame]2.TH E2FREEFRAG 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]3.SH NAME
4e2freefrag \- report free space fragmentation information
5.SH SYNOPSIS
6.B e2freefrag
7[
8.B \-c chunk_kb
9]
10[
11.B \-h
12]
13.B filesys
14
15.SH DESCRIPTION
16.B e2freefrag
17is used to report free space fragmentation on ext2/3/4 file systems.
18.I filesys
19is the filesystem device name (e.g.
20.IR /dev/hdc1 ", " /dev/md0 ).
21The
22.B e2freefrag
23program will scan the block bitmap information to check how many free blocks
24are present as contiguous and aligned free space. The percentage of contiguous
25free blocks of size and of alignment
26.IR chunk_kb
27is reported. It also displays the minimum/maximum/average free chunk size in
28the filesystem, along with a histogram of all free chunks. This information
29can be used to gauge the level of free space fragmentation in the filesystem.
30.SH OPTIONS
31.TP
32.BI \-c " chunk_kb"
Theodore Ts'ocba91c42009-08-09 19:40:14 -0400[diff] [blame]33If a chunk size is specified, then
34.B e2freefrag
35will print how many free chunks of size
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]36.I chunk_kb
Theodore Ts'ocba91c42009-08-09 19:40:14 -0400[diff] [blame]37are available in units of kilobytes (Kb). The chunk size must be a
38power of two and be larger than filesystem block size.
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]39.TP
40.BI \-h
41Print the usage of the program.
42.SH EXAMPLE
43# e2freefrag /dev/vgroot/lvhome
44.br
45Device: /dev/vgroot/lvhome
46.br
47Blocksize: 4096 bytes
48.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]49Total blocks: 1504085
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]50.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]51Free blocks: 292995 (19.5%)
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]52.br
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]53
Theodore Ts'oaff2cf82009-08-09 19:29:30 -0400[diff] [blame]54Min. free extent: 4 KB
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]55.br
Theodore Ts'oaff2cf82009-08-09 19:29:30 -0400[diff] [blame]56Max. free extent: 24008 KB
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]57.br
Theodore Ts'oaff2cf82009-08-09 19:29:30 -0400[diff] [blame]58Avg. free extent: 252 KB
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]59.br
60
Theodore Ts'oaff2cf82009-08-09 19:29:30 -0400[diff] [blame]61HISTOGRAM OF FREE EXTENT SIZES:
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]62.br
Theodore Ts'oaff2cf82009-08-09 19:29:30 -0400[diff] [blame]63Extent Size Range : Free extents Free Blocks Percent
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]64.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]65 4K... 8K- : 704 704 0.2%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]66.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]67 8K... 16K- : 810 1979 0.7%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]68.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]69 16K... 32K- : 843 4467 1.5%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]70.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]71 32K... 64K- : 579 6263 2.1%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]72.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]73 64K... 128K- : 493 11067 3.8%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]74.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]75 128K... 256K- : 394 18097 6.2%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]76.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]77 256K... 512K- : 281 25477 8.7%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]78.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]79 512K... 1024K- : 253 44914 15.3%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]80.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]81 1M... 2M- : 143 51897 17.7%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]82.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]83 2M... 4M- : 73 50683 17.3%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]84.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]85 4M... 8M- : 37 52417 17.9%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]86.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]87 8M... 16M- : 7 19028 6.5%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]88.br
Andreas Dilgerad751f12009-07-24 18:32:25 -0400[diff] [blame]89 16M... 32M- : 1 6002 2.0%
Theodore Ts'o0b2681f2009-07-22 03:40:58 -0400[diff] [blame]90.SH AUTHOR
91This version of e2freefrag was written by Rupesh Thakare, and modified by
92Andreas Dilger <adilger@sun.com>, and Kalpak Shah.
93.SH SEE ALSO
94.IR debugfs (8),
95.IR dumpe2fs (8),
96.IR e2fsck (8)