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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 filesys-
              tem 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 <adilgerATsun.com>, and
       Kalpak Shah.

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



E2fsprogs version 1.41.12          May 2010                      E2FREEFRAG(8)