Operating System/Virtual Storage (OS/VS)

Meaning – The term Operating System/Virtual Storage (OS/VS), refers to a family of operating systems that control IBM System/360 and System/370 computing systems. OS/VS includes VS1, VS2, MVS/370, and MVS/XA.

z/OS uses both types of physical storage (central and auxiliary) to enable another kind of storage called virtual storage. In z/OS, each user has access to virtual storage, rather than physical storage. This use of virtual storage is central to the unique ability of z/OS to interact with large numbers of users concurrently while processing the largest workloads.

Virtual storage means that each running program can assume it has access to all of the storage defined by the architecture’s addressing scheme. The only limit is the number of bits in a storage address. This ability to use a large number of storage locations is important because a program may be long and complex, and both the program’s code and the data it requires must be in central storage for the processor to access them.

Example of usage“Virtual storage, then, is this combination of real and auxiliary storage. z/OS uses a series of tables and indexes to relate locations on auxiliary storage to locations in central storage.”