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E2FREEFRAG(8)									    E2FREEFRAG(8)

NAME
       e2freefrag - report free space fragmentation information

SYNOPSIS
       e2freefrag [ -c chunk_kb ] [ -h ] filesys

DESCRIPTION
       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.

OPTIONS
       -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.

EXAMPLE
       # 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%

AUTHOR
       This  version  of e2freefrag was written by Rupesh Thakare, and modified by Andreas Dilger
       <adilger@sun.com>, and Kalpak Shah.

SEE ALSO
       debugfs(8), dumpe2fs(8), e2fsck(8)

E2fsprogs version 1.41.14		  December 2010 			    E2FREEFRAG(8)
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