phpman > man > e2freefrag(8)

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 AT sun.com>, and Kalpak Shah.

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



E2fsprogs version 1.46.5                    December 2021                              E2FREEFRAG(8)