A volume made up of disk space on more than one physical disk. A spanned volume can also consist of two or more noncontiguous areas on a single disk. You can add more space to a spanned volume by extending it at any time. You can create spanned volumes only on dynamic disks. Spanned volumes are not fault tolerant. In Windows NT 4.0 Disk Administrator, a spanned volume is known as a volume set. See also Dynamic disk, Dynamic volume, Fault tolerance, Simple volume.

a concatenated volume with sections of disk space spread across more than one disk

A method of extending an simple volume beyond one drive.