volume set (n)~ A volume that consists of disk space on one or more physical disks. A volume set is created by using basic disks and is supported only in WindowsNT4.0 or earlier. Volume sets were replaced by spanned volumes which use dynamic disks. Volume Shadow Copy Service (n)~ A Windows Server 2003 technology that supports creation of single point-in-time shadow copies - also known as snapshots - of single or multiple volumes without impacting file server performance. Volume Shadow Copy Service also supports backups of open files.