1E2FREEFRAG(8)               System Manager's Manual              E2FREEFRAG(8)
2
3
4

NAME

6       e2freefrag - report free space fragmentation information
7

SYNOPSIS

9       e2freefrag [ -c chunk_kb ] [ -h ] filesys
10
11

DESCRIPTION

13       e2freefrag  is used to report free space fragmentation on ext2/3/4 file
14       systems.  filesys is  the  filesystem  device  name  (e.g.   /dev/hdc1,
15       /dev/md0).   The e2freefrag program will scan the block bitmap informa‐
16       tion to check how many  free  blocks  are  present  as  contiguous  and
17       aligned  free  space.  The percentage of contiguous free blocks of size
18       and of alignment chunk_kb is reported.   It  also  displays  the  mini‐
19       mum/maximum/average  free  chunk  size  in the filesystem, along with a
20       histogram of all free chunks.  This information can be  used  to  gauge
21       the level of free space fragmentation in the filesystem.
22

OPTIONS

24       -c chunk_kb
25              If  a  chunk  size  is specified, then e2freefrag will print how
26              many free chunks of size chunk_kb  are  available  in  units  of
27              kilobytes  (Kb).   The  chunk size must be a power of two and be
28              larger than filesystem block size.
29
30       -h     Print the usage of the program.
31

EXAMPLE

33       # e2freefrag /dev/vgroot/lvhome
34       Device: /dev/vgroot/lvhome
35       Blocksize: 4096 bytes
36       Total blocks: 1504085
37       Free blocks: 292995 (19.5%)
38
39       Min. free extent: 4 KB
40       Max. free extent: 24008 KB
41       Avg. free extent: 252 KB
42
43       HISTOGRAM OF FREE EXTENT SIZES:
44       Extent Size Range :   Free extents   Free Blocks  Percent
45           4K...    8K- :           704           704     0.2%
46           8K...   16K- :           810          1979     0.7%
47          16K...   32K- :           843          4467     1.5%
48          32K...   64K- :           579          6263     2.1%
49          64K...  128K- :           493         11067     3.8%
50         128K...  256K- :           394         18097     6.2%
51         256K...  512K- :           281         25477     8.7%
52         512K... 1024K- :           253         44914    15.3%
53           1M...    2M- :           143         51897    17.7%
54           2M...    4M- :            73         50683    17.3%
55           4M...    8M- :            37         52417    17.9%
56           8M...   16M- :             7         19028     6.5%
57          16M...   32M- :             1          6002     2.0%
58

AUTHOR

60       This version of e2freefrag was written by Rupesh Thakare, and  modified
61       by Andreas Dilger <adilger@sun.com>, and Kalpak Shah.
62

SEE ALSO

64       debugfs(8), dumpe2fs(8), e2fsck(8)
65
66
67
68E2fsprogs version 1.45.3           July 2019                     E2FREEFRAG(8)
Impressum