| .\" -*- nroff -*- |
| .TH E2FREEFRAG 8 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@" |
| .SH NAME |
| e2freefrag \- report free space fragmentation information |
| .SH SYNOPSIS |
| .B e2freefrag |
| [ |
| .B \-c chunk_kb |
| ] |
| [ |
| .B \-h |
| ] |
| .B filesys |
| |
| .SH DESCRIPTION |
| .B e2freefrag |
| is used to report free space fragmentation on ext2/3/4 file systems. |
| .I filesys |
| is the filesystem device name (e.g. |
| .IR /dev/hdc1 ", " /dev/md0 ). |
| The |
| .B 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 |
| .IR 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. |
| .SH OPTIONS |
| .TP |
| .BI \-c " chunk_kb" |
| If a chunk size is specified, then |
| .B e2freefrag |
| will print how many free chunks of size |
| .I 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. |
| .TP |
| .BI \-h |
| Print the usage of the program. |
| .SH EXAMPLE |
| # e2freefrag /dev/vgroot/lvhome |
| .br |
| Device: /dev/vgroot/lvhome |
| .br |
| Blocksize: 4096 bytes |
| .br |
| Total blocks: 1504085 |
| .br |
| Free blocks: 292995 (19.5%) |
| .br |
| |
| Min. free extent: 4 KB |
| .br |
| Max. free extent: 24008 KB |
| .br |
| Avg. free extent: 252 KB |
| .br |
| |
| HISTOGRAM OF FREE EXTENT SIZES: |
| .br |
| Extent Size Range : Free extents Free Blocks Percent |
| .br |
| 4K... 8K- : 704 704 0.2% |
| .br |
| 8K... 16K- : 810 1979 0.7% |
| .br |
| 16K... 32K- : 843 4467 1.5% |
| .br |
| 32K... 64K- : 579 6263 2.1% |
| .br |
| 64K... 128K- : 493 11067 3.8% |
| .br |
| 128K... 256K- : 394 18097 6.2% |
| .br |
| 256K... 512K- : 281 25477 8.7% |
| .br |
| 512K... 1024K- : 253 44914 15.3% |
| .br |
| 1M... 2M- : 143 51897 17.7% |
| .br |
| 2M... 4M- : 73 50683 17.3% |
| .br |
| 4M... 8M- : 37 52417 17.9% |
| .br |
| 8M... 16M- : 7 19028 6.5% |
| .br |
| 16M... 32M- : 1 6002 2.0% |
| .SH AUTHOR |
| This version of e2freefrag was written by Rupesh Thakare, and modified by |
| Andreas Dilger <adilger@sun.com>, and Kalpak Shah. |
| .SH SEE ALSO |
| .IR debugfs (8), |
| .IR dumpe2fs (8), |
| .IR e2fsck (8) |