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📛 NAME

e2freefrag - report free space fragmentation information

🚀 Quick Reference

Use Case	Command	Description
Check free space fragmentation	e2freefrag /dev/sda1	Scan block bitmap and report free space fragmentation, including histogram of free extent sizes.
Specify chunk size for alignment analysis	e2freefrag -c 4096 /dev/sda1	Report how many free chunks of size chunk_kb are available, with alignment information.
Display help	e2freefrag -h	Print usage information and exit.

📋 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

📛 NAME 🚀 Quick Reference 📋 SYNOPSIS 📖 DESCRIPTION ⚙️ OPTIONS 💡 EXAMPLE 👤 AUTHOR 🔗 SEE ALSO