(MVS/System Extensions), next to MVS/SP (MVS/System Product) Version 1, next to MVS/XA (MVS/eXtended Architecture), next to MVS/ESA (MVS/Enterprise Systems Architecture)
VM/ESA (these cards were fully compatible with S/370 and S/390 mainframes, and could run any S/370 operating system from the 31-bit era, e.g., MVS/ESA,
hierarchical file system for the MVS/ESA/SP through z/OS operating systems. IBM introduced HFS on February 9, 1993 in MVS/ESA System Product Version 4 Release
MVS/XA) MVS/System Product Version 3 (MVS/Enterprise Systems Architecture, MVS/ESA) MVS/ESA SP Version 4 MVS/ESA SP Version 5 Some, e.g., TSO/E, are bundled
2 GiB (231 bytes). In z/OS, the storage layout is similar to that of MVS/XA, MVS/ESA and OS/390; storage above the 2 GiB bar is managed by different services