filefrag(8) — Linux manual page


FILEFRAG(8)              System Manager's Manual             FILEFRAG(8)

NAME         top

       filefrag - report on file fragmentation

SYNOPSIS         top

       filefrag [ -bblocksize ] [ -BeEkPsvVxX ] [ files...  ]

DESCRIPTION         top

       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         top

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

              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

       -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

       -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         top

       filefrag was written by Theodore Ts'o <>.

COLOPHON         top

       This page is part of the e2fsprogs (utilities for ext2/3/4
       filesystems) project.  Information about the project can be found
       at ⟨⟩.  It is not known how to
       report bugs for this man page; if you know, please send a mail to  This page was obtained from the project's
       upstream Git repository
       ⟨git://⟩ on
       2024-06-14.  (At that time, the date of the most recent commit
       that was found in the repository was 2024-05-20.)  If you
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E2fsprogs version 1.47.1        May 2024                     FILEFRAG(8)