Library /sys$common/syshlp/bkm$help.hlb Backup defrag  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Restoring a volume to eliminate disk fragmentation

    During the course of creating, deleting, and modifying files, a disk
    can have sections of files scattered across it.  The files, though
    scattered, are linked by software so that a file appears contiguous
    when it is displayed for you.  Eventually the disk can become
    severely fragmented, and system performance suffers.

    When a disk stores files contiguously, system performance improves,
    and the wear and tear on the disk mechanisms is minimized because
    fewer searches are performed for the sections of a file.

    When you restore a volume from a save set, BACKUP Manager
    places the files contiguously on the disk.  To eliminate disk
    fragmentation, you can perform a backup of the disk and restore the
    backup copy.