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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLE | AUTHOR | SEE ALSO | COLOPHON |
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E2FREEFRAG(8) System Manager's Manual E2FREEFRAG(8)
e2freefrag - report free space fragmentation information
e2freefrag [ -c chunk_kb ] [ -h ] filesys
e2freefrag is used to report free space fragmentation on ext2/3/4
file systems. filesys is the filesystem device name (e.g.
/dev/hdc1, /dev/md0). The e2freefrag program will scan the block
bitmap information to check how many free blocks are present as
contiguous and aligned free space. The percentage of contiguous free
blocks of size and of alignment chunk_kb is reported. It also
displays the minimum/maximum/average free chunk size in the
filesystem, along with a histogram of all free chunks. This
information can be used to gauge the level of free space
fragmentation in the filesystem.
-c chunk_kb
If a chunk size is specified, then e2freefrag will print how
many free chunks of size chunk_kb are available in units of
kilobytes (Kb). The chunk size must be a power of two and be
larger than filesystem block size.
-h Print the usage of the program.
# e2freefrag /dev/vgroot/lvhome
Device: /dev/vgroot/lvhome
Blocksize: 4096 bytes
Total blocks: 1504085
Free blocks: 292995 (19.5%)
Min. free extent: 4 KB
Max. free extent: 24008 KB
Avg. free extent: 252 KB
HISTOGRAM OF FREE EXTENT SIZES:
Extent Size Range : Free extents Free Blocks Percent
4K... 8K- : 704 704 0.2%
8K... 16K- : 810 1979 0.7%
16K... 32K- : 843 4467 1.5%
32K... 64K- : 579 6263 2.1%
64K... 128K- : 493 11067 3.8%
128K... 256K- : 394 18097 6.2%
256K... 512K- : 281 25477 8.7%
512K... 1024K- : 253 44914 15.3%
1M... 2M- : 143 51897 17.7%
2M... 4M- : 73 50683 17.3%
4M... 8M- : 37 52417 17.9%
8M... 16M- : 7 19028 6.5%
16M... 32M- : 1 6002 2.0%
This version of e2freefrag was written by Rupesh Thakare, and
modified by Andreas Dilger <adilger@sun.com>, and Kalpak Shah.
debugfs(8), dumpe2fs(8), e2fsck(8)
This page is part of the e2fsprogs (utilities for ext2/3/4
filesystems) project. Information about the project can be found at
⟨http://e2fsprogs.sourceforge.net/⟩. It is not known how to report
bugs for this man page; if you know, please send a mail to
man-pages@man7.org. This page was obtained from the project's
upstream Git repository
⟨git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git⟩ on 2018-02-02.
(At that time, the date of the most recent commit that was found in
the repository was 2018-01-03.) If you discover any rendering prob‐
lems in this HTML version of the page, or you believe there is a bet‐
ter or more up-to-date source for the page, or you have corrections
or improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to man-pages@man7.org
E2fsprogs version 1.43.8 January 2018 E2FREEFRAG(8)
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