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 file system 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 file system, along with
       a histogram of all free chunks.	This information can be used to gauge
       the level of free space fragmentation in the file system.

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 file system 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 1.47.3	   July 2025			 E2FREEFRAG(8)