NAME | SYNOPSIS | DESCRIPTION | FILES | SEE ALSO | NOTES | COLOPHON

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

NAME         top

       xfs_fsr - filesystem reorganizer for XFS

SYNOPSIS         top

       xfs_fsr [-vdg] [-t seconds] [-p passes] [-f leftoff] [-m mtab]
       xfs_fsr [-vdg] [xfsdev | file] ...
       xfs_fsr -V

DESCRIPTION         top

       xfs_fsr is applicable only to XFS filesystems.

       xfs_fsr improves the organization of mounted filesystems.  The
       reorganization algorithm operates on one file at a time, compacting
       or otherwise improving the layout of the file extents (contiguous
       blocks of file data).

       The following options are accepted by xfs_fsr.  The -m, -t, and -f
       options have no meaning if any filesystems or files are specified on
       the command line.

       -m mtab      Use this file for the list of filesystems to reorganize.
                    The default is to use /etc/mtab.

       -t seconds   How long to reorganize.  The default is 7200 seconds (2
                    hours).

       -p passes    Number of passes before terminating global re-org.  The
                    default is 10 passes.

       -f leftoff   Use this file instead of /var/tmp/.fsrlast to read the
                    state of where to start and as the file to store the
                    state of where reorganization left off.

       -v           Verbose.  Print cryptic information about each file
                    being reorganized.

       -d           Debug.  Print even more cryptic information.

       -g           Print to syslog (default if stdout not a tty).

       -V           Prints the version number and exits.

       When invoked with no arguments xfs_fsr reorganizes all regular files
       in all mounted filesystems.  xfs_fsr makes many cycles over /etc/mtab
       each time making a single pass over each XFS filesystem.  Each pass
       goes through and selects files that have the largest number of
       extents.  It attempts to defragment the top 10% of these files on
       each pass.

       It runs for up to two hours after which it records the filesystem
       where it left off, so it can start there the next time.  This
       information is stored in the file /var/tmp/.fsrlast_xfs.  If the
       information found here is somehow inconsistent or out of date it is
       ignored and reorganization starts at the beginning of the first
       filesystem found in /etc/mtab.

       xfs_fsr can be called with one or more arguments naming filesystems
       (block device name), and files to reorganize.  In this mode xfs_fsr
       does not read or write /var/tmp/.fsrlast_xfs nor does it run for a
       fixed time interval.  It makes one pass through each specified
       regular file and all regular files in each specified filesystem.  A
       command line name referring to a symbolic link (except to a file
       system device), FIFO, or UNIX domain socket generates a warning
       message, but is otherwise ignored.  While traversing the filesystem
       these types of files are silently skipped.

FILES         top

       /etc/mtab            contains default list of filesystems to
                            reorganize.
       /var/tmp/.fsrlast_xfs
                            records the state where reorganization left off.

SEE ALSO         top

       xfs_fsr(8), mkfs.xfs(8), xfs_ncheck(8), xfs(5).

NOTES         top

       xfs_fsr improves the layout of extents for each file by copying the
       entire file to a temporary location and then interchanging the data
       extents of the target and temporary files in an atomic manner.  This
       method requires that enough free disk space be available to copy any
       given file and that the space be less fragmented than the original
       file.  It also requires the owner of the file to have enough
       remaining filespace quota to do the copy on systems running quotas.
       xfs_fsr generates a warning message if space is not sufficient to
       improve the target file.

       A temporary file used in improving a file given on the command line
       is created in the same parent directory of the target file and is
       prefixed by the string '.fsr'.  The temporary files used in improving
       an entire XFS device are stored in a directory at the root of the
       target device and use the same naming scheme.  The temporary files
       are unlinked upon creation so data will not be readable by any other
       process.

       xfs_fsr does not operate on files that are currently mapped in
       memory.  A 'file busy' error can be seen for these files if the
       verbose flag (-v) is set.

       Files marked as no-defrag will be skipped. The xfs_io(8) chattr
       command with the f attribute can be used to set or clear this flag.
       Files and directories created in a directory with the no-defrag flag
       will inherit the attribute.

       An entry in /etc/mtab or the file specified using the -m option must
       have the rw option specified for read and write access.  If this
       option is not present, then xfs_fsr skips the filesystem described by
       that line.  See the fstab(5) reference page for more details.

       In general we do not foresee the need to run xfs_fsr on system
       partitions such as /, /boot and /usr as in general these will not
       suffer from fragmentation.  There are also issues with defragmenting
       files lilo(8) uses to boot your system. It is recommended that these
       files should be flagged as no-defrag with the xfs_io(8) chattr
       command. Should these files be moved by xfs_fsr then you must rerun
       lilo before you reboot or you may have an unbootable system.

COLOPHON         top

       This page is part of the xfsprogs (utilities for XFS filesystems)
       project.  Information about the project can be found at 
       ⟨http://xfs.org/⟩.  If you have a bug report for this manual page, see
       ⟨http://oss.sgi.com/bugzilla/buglist.cgi?product=XFS⟩.  This page was
       obtained from the project's upstream Git repository 
       ⟨git://oss.sgi.com/xfs/cmds/xfsprogs⟩ on 2017-09-15.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

                                                                  xfs_fsr(8)

Pages that refer to this page: xfs_bmap(8)