FILEFRAG(8) System Manager's Manual FILEFRAG(8)
NAME
filefrag - report on file fragmentation
SYNOPSIS
filefrag [ -bblocksize ] [ -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.
-bblocksize
Use blocksize in bytes, or with [KMG] suffix, up to 1GB for out-
put 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 argu-
ment, 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 fea-
ture 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>.
E2fsprogs version 1.47.0 February 2023 FILEFRAG(8)
Generated by dwww version 1.16 on Tue Dec 16 17:08:48 CET 2025.