Z/OS

IBM z/OSzOSIBM zIBM's z/OS
z/OS is a 64-bit operating system for IBM mainframes, produced by IBM.wikipedia
261 Related Articles

CICS

Customer Information Control SystemCICS Transaction ServerIBM Customer Information Control System
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
Customer Information Control System (CICS) is a family of mixed language application servers that provide online transaction management and connectivity for applications on IBM mainframe systems under z/OS and z/VSE.

IBM Db2 Family

DB2IBM DB2pureQuery
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
DB2 9 for z/OS was announced in early 2007.

Resource Access Control Facility

RACFRAC/F
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
It is a security system that provides access control and auditing functionality for the z/OS and z/VM operating systems.

IBM MQ

WebSphere MQIBM WebSphere MQMQ
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
MQ is available on a large number of platforms (both IBM and non-IBM), including z/OS (mainframe), OS/400 (IBM System i or AS/400), Transaction Processing Facility, UNIX (AIX, HP-UX, Solaris), HP NonStop, OpenVMS, Linux, and Microsoft Windows.

Operating system

operating systemsOScomputer operating system
z/OS is a 64-bit operating system for IBM mainframes, produced by IBM.

ISPF

Structured Programming FacilityISPF/PDFProgram Development Facility
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
In computing, Interactive System Productivity Facility (ISPF) is a software product for many historic IBM mainframe operating systems and currently the z/OS operating system that runs on IBM mainframes.

IBM Information Management System

IMSInformation Management SystemHierarchical Sequential Access Method
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
In the interim period, IMS has undergone many developments as IBM System/360 technology evolved into the current z/OS and IBM zEnterprise System technologies.

Job Control Language

JCLjob controlDD statement
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
Right from the start, JCL for the OS family (up to and including z/OS) was more flexible and easier to use.

OS/390

It derives from and is the successor to OS/390, which in turn followed a string of MVS versions.
In December 2001 IBM extended OS/390 to include support for 64-bit zSeries processors and added various other improvements, and the result is now named z/OS.

UNIX System Services

OpenEdition MVSUSSOpenEdition
However, z/OS also supports 64-bit Java, C, C++, and UNIX (Single UNIX Specification) APIs and applications through UNIX System Services – The Open Group certifies z/OS as a compliant UNIX operating system – with UNIX/Linux-style hierarchical HFS and zFS file systems.
UNIX System Services (USS) is a required, included component of z/OS.

Time Sharing Option

TSOMVS/TSOIBM TSO
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.
Time Sharing Option (TSO) is an interactive time-sharing environment for IBM mainframe operating systems, including OS/360 MVT, OS/VS2 (SVS), MVS, OS/390, and z/OS.

ZFS (z/OS file system)

zFSIBM zFSz/OS File System
However, z/OS also supports 64-bit Java, C, C++, and UNIX (Single UNIX Specification) APIs and applications through UNIX System Services – The Open Group certifies z/OS as a compliant UNIX operating system – with UNIX/Linux-style hierarchical HFS and zFS file systems.
z/OS File System (zFS) is a POSIX-style hierarchical file system for IBM's z/OS operating system for z System mainframes, a successor to that operating system's HFS.

Hierarchical File System (IBM MVS)

HFSIBM HFS
However, z/OS also supports 64-bit Java, C, C++, and UNIX (Single UNIX Specification) APIs and applications through UNIX System Services – The Open Group certifies z/OS as a compliant UNIX operating system – with UNIX/Linux-style hierarchical HFS and zFS file systems.
IBM's Hierarchical File System (HFS) is a POSIX-style file system for IBM's z/OS and its predecessor operating systems for z System mainframes.

Single UNIX Specification

SUSUNIX 03UNIX 95
However, z/OS also supports 64-bit Java, C, C++, and UNIX (Single UNIX Specification) APIs and applications through UNIX System Services – The Open Group certifies z/OS as a compliant UNIX operating system – with UNIX/Linux-style hierarchical HFS and zFS file systems.
For instance, IBM OS/390, now z/OS, qualifies as a "Unix" despite having no code in common.

IBM Parallel Sysplex

Parallel SysplexSysplexGDPS
Another central design philosophy is support for extremely high quality of service (QoS), even within a single operating system instance, although z/OS has built-in support for Parallel Sysplex clustering.
In computing, a Parallel Sysplex is a cluster of IBM mainframes acting together as a single system image with z/OS.

Linux on IBM Z

s390xIBM LinuxONEIBM Z
These new functions within the hardware, z/OS, and z/VM — and Linux and OpenSolaris support — have encouraged development of new applications for mainframes.
Microcode restricts IFLs from running "traditional" workloads, such as z/OS, but they are physically identical to other IBM Z processors.

IBM WebSphere Application Server

WebSphere Application ServerWebSphereIBM WebSphere AS
Many of them utilize the WebSphere Application Server for z/OS middleware.
It works with a number of Web servers including Apache HTTP Server, Netscape Enterprise Server, Microsoft Internet Information Services (IIS), IBM HTTP Server for i5/OS, IBM HTTP Server for z/OS, and IBM HTTP Server for AIX/Linux/Microsoft Windows/Solaris.

OS/360 and successors

OS/360MVTOS/MVT
See OS/360 and successors timeline.
Although OS/360 itself was discontinued, successor operating systems including the virtual storage MVS and the 64-bit z/OS are still run and maintain application-level compatibility.

Logical partition

LPARlogical partitioningLogical partition (virtual computing platform)
However, modern IBM mainframes also offer two additional levels of virtualization: LPARs and (optionally) z/VM.
Multiple operating systems are compatible with LPARs, including z/OS, z/VM, z/VSE, z/TPF, AIX, Linux, and i/OS.

MVS

MVS/ESAMVS/XAMVS/370
It derives from and is the successor to OS/390, which in turn followed a string of MVS versions.
Replaced by/renamed as OS/390 late 1995 and subsequently as z/OS.

Access method

access methodsAMHSAM
z/OS supports stable mainframe systems and standards such as CICS, COBOL, IMS, DB2, RACF, SNA, IBM MQ, record-oriented data access methods, REXX, CLIST, SMP/E, JCL, TSO/E, and ISPF, among others.

Intelligent Resource Director

On IBM mainframes running the z/OS operating system, Intelligent Resource Director (IRD) is software that automates the management of CPU resources and certain I/O resources.

Data set (IBM mainframe)

data setdatasetPartitioned Data Sets
When DSN appears, the GDG name appears along with the history number, where
Use of this term began with OS/360 and is still used by its successors, including the current z/OS.

IBM System Management Facilities

SMFSystem Management Facilities
IBM System Management Facility (SMF) is a component of IBM's z/OS for mainframe computers, providing a standardised method for writing out records of activity to a file (or data set to use a z/OS term).

Resource Measurement Facility

RMF is significantly enhanced with every release of the z/OS Operating System – that is approximately once a year – with other enhancements occurring in support of new hardware, such as new processor models.