Manual: e2freefrag

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  fragmenta‐
       tion 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  ,	 and
       Kalpak Shah.

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

E2fsprogs version 1.47.2				January 2025					       E2FREEFRAG(8)