IBM zVM Module 2 Conversational Monitor System CMS

IBM ^ Objectives List z/VM’s base components and describe how they work together Describe CMS and the tasks it can accomplish State why CMS Pipelines are an important feature of z/VM Describe CMS Application Multitasking Describe the XEDIT environment and its purpose © 2004 IBM Corporation

IBM ^ Objectives continued Describe three important application environments that CMS supports: – Callable Service Library (CSL) – Open. Extensions – Reusable Server Kernel Show to find and use the Help Facility Explain Shared File System (SFS) setup and configuration Explain how syntax diagrams are used List and describe the most important and useful CMS commands © 2004 IBM Corporation

IBM ^ Introducing z/VM’s Base Components Conversational Monitor System (CMS) An end-user interface for running user programs A single user interactive environment Control Program (CP) A component that manages the resources of a single system to make it appear that multiple computing systems exist REXX/VM A programming language that allows you to write customized application programs and command procedures Group Control System (GCS) A virtual machine supervisor that provides multitasking services © 2004 IBM Corporation

IBM ^ What is CMS? Conversational Monitor System is an operating system environment itself Over time CMS became a part of VM CMS is a single user operating system, which makes it possible to: Create and maintain files Write and execute application programs CMS communicates with users through the console © 2004 IBM Corporation

IBM ^ CMS Tasks With CMS, you can: Write, test, and debug application programs for use on CMS or guest systems Run application programs developed on CMS or guest systems Create and edit data files Process jobs in batch mode Share data between CMS and guest systems Communicate with other system users © 2004 IBM Corporation

IBM ^ Structure of CMS © 2004 IBM Corporation

IBM ^ Callable Services Library (CSL) © 2004 IBM Corporation

IBM ^ CMS Pipelines Provide a rich and efficient set of functions that can be used to solve large problems by breaking them up into smaller programs Smaller programs are called stages Stages: Read data Filter and refine data Combine multiple data items “Unix/Linux like” © 2004 IBM Corporation

IBM ^ CMS Pipelines © 2004 IBM Corporation

IBM ^ CMS Application Multitasking An application can be divided into multiple units of execution, called threads. Threads have the ability to run on multiple CPUs at the same time Multitasking facilities allow applications to harness the power of the underlying multiprocessor complex to achieve high performance. © 2004 IBM Corporation

IBM ^ Open. Extensions provides open systems support in two ways: Open. Extensions Services Open. Extensions Shell and Utilities Open. Extensions Services include: POSIX. 1—System Interfaces POSIX. 1 a—Extensions to POSIX. 1 c—Threads POSIX programs should “port” to CMS. © 2004 IBM Corporation

IBM ^ Open. Extensions – Invocation from REXX Procedures example OPENVM is a z/VM subcommand environment OPENVM makes invocation of callable services look like other requests for host functions The OPENVM language binding file defines REXX variables used by the Open. Extensions services. You include the file using the APILOAD function. © 2004 IBM Corporation

IBM ^ Reusable Server Kernel. . . ”reentrant” Enables vendors and application programmers to write multithreaded server programs The server kernel is the starting point for a server program To construct a server program you need: A text library of routines A macro library of function prototypes Constant definitions These entities are supplied by the Reusable Server Kernel © 2004 IBM Corporation

IBM ^ Additional RSK Help Areas …. . RSK = Reusable server kernel Connectivity DASD I/O Authorization Memory management Runtime environment Worker machines Configuration and operation © 2004 IBM Corporation

IBM ^ XEDIT. . . . skip this. . . its a WYSIWYG editor

IBM ^ XEDIT continued © 2004 IBM Corporation

IBM ^ The Batch Facility Can take over both short and long processing jobs for you Frees up your time to continue working at your terminal Two examples: – Have the facility format text and send it to the printer, instead of doing it yourself – Have large jobs run throughout the night to take advantage of lower computing costs or lighter loads © 2004 IBM Corporation

IBM ^ How the VM Batch Facility Works The process starts when you submit a job to the VM Batch Facility – a monitor VM and task VM The monitor virtual machine receives your job and holds it until it can start: A task virtual machine runs your job The monitor machine periodically checks your job while it runs Your commands can retrieve the status of a job, change how and when it is to run, and cancel a job When your job is completed, the task machine logs off and is ready for another job © 2004 IBM Corporation

IBM ^ z/VM Help Facility CMS Help Facility provide assistance for: Tasks Commands and options Subcommands REXX statements Callable routines Pipeline stages Assembler language macros Messages © 2004 IBM Corporation

IBM ^ Shared File System (SFS) Files are stored in file pools A user can be given an amount of file space in a pool The files in a file space are organized in directories A file can be placed in more than one directory © 2004 IBM Corporation

IBM ^ Shared File System (SFS) continued Users can grant each other authorities for files or directories Multiple users can have concurrent access to the same file or directory Locks on files and directories ensure data integrity among multiple users You can share files and directories with users on other systems © 2004 IBM Corporation

IBM ^ Syntax Diagrams (basics) Read syntax diagrams from left to right and from

IBM ^ CMS Commands © 2004 IBM Corporation

IBM ^ QUERY – Usage Notes © 2004 IBM Corporation

IBM ^ ACCESS – Usage Notes Using the ACCESS command with a directory ID or a device number – With and without a file pool Using the ACCESS command with a directory ID – Determining status by ownership Using the ACCESS command with a virtual device number – Access can create a file directory in your virtual machine when one is not present © 2004 IBM Corporation

IBM ^ RELEASE The RELEASE Command is used to free an accessed disk that

IBM ^ RELEASE If you want to release and detach the 498 disk that is accessed as your file mode b, then issue: release 498 (det OR -- release b (det To just release the disk currently accessed as file mode c, issue: release c © 2004 IBM Corporation

IBM ^ FORMAT – Usage Notes Examples of RECOMP and LABEL: – format 192 b (recomp) – format 193 c (label) Formatting a disk requires heavy processor utilization, so can be slow and affect performance Choose the appropriate block size to optimize: – space utilization – performance Automatic formatting is possible on the 192 disk © 2004 IBM Corporation

IBM ^ Conclusion CMS – Conversational Monitor System Is a operating system that runs within z/VM CMS tasks include writing, testing, and debugging application programs to be used by CMS or z/VM guest systems CMS runs the full-screen editing facility called XEDIT The CMS help facility is a CMS Command that can be accessed when help is needed by entering: help cms © 2004 IBM Corporation

IBM ^ Glossary Conversational Monitor System (CMS)- A component of z/VM that runs in a virtual machine and provides both the interactive z/VM end-user interface and the general z/VM application programming interface. CMS runs only under the control of the z/VM Control Program (CP). CMS Pipelines- CMS job control product for z/VM that enables complex tasks to be specified and executed. CMS Pipelines has three parts – a command parser, a library of built-in programs, and a dispatcher. Callable Services Library-A package of CMS routines that can be stored as an entity and made available to a high-level language, REXX, or an assembler program. © 2004 IBM Corporation

IBM ^ Glossary File pool-A collection of minidisks managed by a file pool server. It contains user files and directories and associated control information. The files and directories for many users can be contained in a single file pool. Group Control System (GCS)- A component of z/VM, consisting of a named saved system that the user can IPL and run in a virtual machine. It provides simulated MVS services and unique supervisor services to help support a native SNA network. Initial Program Load (IPL)- The process of loading an operating system into a machine Open. Extensions Services- The VM implementation of three POSIX standards © 2004 IBM Corporation

IBM ^ Glossary Open. Extensions Shell and Utilities- provides application development tools and an interactive environment in support of the POSIX application environment. REXX/VM- (REstructed e. Xtended e. Xecutor programming language) processes English-like commands. XEDIT- A full-screen editing facility that runs under CMS. © 2004 IBM Corporation

IBM ^ References CMS Command Utility Reference. Manual Number: SC 246010 -02. Third Edition (May 2002). CMS User’s Guide. Manual Number: SC 24 -6009 -00. First Edition (July 2001). © 2004 IBM Corporation