E2FREEFRAG(8)						      System Manager's Manual						     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 mini-
       mum/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 1.41.11					    March 2010							     E2FREEFRAG(8)