filefrag(8) — Linux manual page


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

NAME         top

       filefrag - report on file fragmentation

SYNOPSIS         top

       filefrag [ -bblocksize ] [ -BeksvxX ] [ files...  ]

DESCRIPTION         top

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

       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 filesystem blocksize.  For compatibility
              with earlier versions of filefrag, if blocksize is unspecified
              it defaults to 1024 bytes.

       -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.

       -P     Pre-load the ext4's extent status cache for the file.  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 '-b 1024').

       -s     Sync the file before requesting the mapping.

       -v     Be verbose when checking for file fragmentation.

       -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 2020-09-18.
       (At that time, the date of the most recent commit that was found in
       the repository was 2020-03-21.)  If you discover any rendering prob‐
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E2fsprogs version 1.46-WIP       March 2020                      FILEFRAG(8)