E2FREEFRAG(8)             (August 2021)             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 avail-
               able 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%

     Page 1              E2fsprogs version 1.46.4    (printed 5/23/22)

     E2FREEFRAG(8)             (August 2021)             E2FREEFRAG(8)

            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)

     Page 2              E2fsprogs version 1.46.4    (printed 5/23/22)