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 informa- tion 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 mini- mum/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 filesystem 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 1.41.12 May 2010 E2FREEFRAG(8)