19.25 Defragmenting an XFS File System

You can use the xfs_fsr command to defragment whole XFS file systems or individual files within an XFS file system. As XFS is an extent-based file system, it is usually unnecessary to defragment a whole file system, and doing so is not recommended.

To defragment an individual file, specify the name of the file as the argument to xfs_fsr.

# xfs_fsr pathname

If you run the xfs_fsr command without any options, the command defragments all currently mounted, writeable XFS file systems that are listed in /etc/mtab. For a period of two hours, the command passes over each file system in turn, attempting to defragment the top ten percent of files that have the greatest number of extents. After two hours, the command records its progress in the file /var/tmp/.fsrlast_xfs, and it resumes from that point if you run the command again.

For more information, see the xfs_fsr(8) manual page.