OS/VS may refer to one of a number of IBM operating systems for System/370 and successors characterized by the use of virtual storage (VS):IBM OS/VS1, successor to MFT II, 1972-1984 IBM OS/VS2, successor to MVT, including: OS/VS2 version 1, also known as SVS, 1972-1974 OS/VS2 version 2, also known as MVS, 1974-1981