---
name: "filefrag"
section: "8"
platform: "linux"
package: "e2fsprogs"
version: "1.47.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/filefrag"
---

# filefrag(8)

report on file fragmentation

## NAME

filefrag - report on file fragmentation

## SYNOPSIS

**filefrag** \[ **-b***blocksize* \] \[ **-BeEkPsvVxX** \] \[ *files...* \]

## DESCRIPTION

**filefrag** reports on how badly fragmented a particular file might be.  It makes allowances for indirect blocks for ext2 and ext3 file systems, but can be used on files for any file system.

The **filefrag** program initially attempts to get the extent information using FIEMAP ioctl which is more efficient and faster. If FIEMAP is not supported then filefrag will fall back to using FIBMAP.

## OPTIONS

- **-B**

  Force the use of the older FIBMAP ioctl instead of the FIEMAP ioctl for testing purposes.

- **-b***blocksize*

  Use *blocksize* in bytes, or with \[KMG\] suffix, up to 1GB for output instead of the file system blocksize.  For compatibility with earlier versions of **filefrag**, if *blocksize* is unspecified it defaults to 1024 bytes.  Since *blocksize* is an optional argument, it must be added without any space after **-b**.

- **-e**

  Print output in extent format, even for block-mapped files.

- **-E**

  Display the contents of ext4's extent status cache.  This feature is not supported on all kernels, and is only supported on ext4 file systems.

- **-k**

  Use 1024-byte blocksize for output (identical to '-b1024').

- **-P**

  Pre-load the ext4 extent status cache for the file.  This is not supported on all kernels, and is only supported on ext4 file systems.

- **-s**

  Sync the file before requesting the mapping.

- **-v**

  Be verbose when checking for file fragmentation.

- **-V**

  Print version number of program and library.  If given twice, also print the FIEMAP flags that are understood by the current version.

- **-x**

  Display mapping of extended attributes.

- **-X**

  Display extent block numbers in hexadecimal format.

## AUTHOR

**filefrag** was written by Theodore Ts'o \<tytso@mit.edu\>.