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z/VM Module 2: Conversational Monitor System (CMS)
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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
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Objectives continued
Describe the three important application environments that CMS supports:
– Callable Service Library (CSL)– OpenExtensions– Reusable Server Kernel
Show how 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
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Introducing z/VM’s Base Components
Conversational Monitor System (CMS) An end-user interface for running user programs
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
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Introducing z/VM’s Base Components continued
Transparent Services Access Facility (TSAF) APPC/VM VTAM Support (AVS) Virtual Machine Serviceability Enhancements Staged/Extended
(VMSES/E) Dump Viewing Facility
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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
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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
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Structure of CMS
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Callable Services Library (CSL)
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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
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CMS Pipelines
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Pipeline Example
pipe < profile exec | count lines | console
This command executes the number of lines contained within your PROFILE EXEC file.
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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.
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OpenExtensions
OpenExtensions provides open systems support in two ways: OpenExtensions Services
OpenExtensions Shell and Utilities OpenExtensions Services include:
POSIX.1—System Interfaces
POSIX.1a—Extensions to POSIX.1
POSIX.1c—Threads
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OpenExtensions – Invocation
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 OpenExtensions services. You include the file using the APILOAD function.
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Reusable Server Kernel
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
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Additional RSK Help Areas
Connectivity DASD I/O Authorization Memory management Runtime environment Worker machines Configuration and operation
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XEDIT
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XEDIT continued
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XEDIT continued
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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
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How the VM Batch Facility Works
The process starts when you submit a job to the VM Batch Facility 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
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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
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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
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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
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Syntax Diagrams (basics)
Read syntax diagrams from left to right and from top to bottom This side module shows you descriptions and examples
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CMS Commands
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QUERY
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QUERY – Usage Notes
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SET
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ACCESS
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ACCESS
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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
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RELEASE
The RELEASE Command is used to free an accessed disk that was previously accessed with the ACCESS Command.
Example:release 0293
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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
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FORMAT
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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
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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
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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.
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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
OpenExtensions Services- The VM implementation of three POSIX standards
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Glossary
OpenExtensions Shell and Utilities- provides application development tools and an interactive environment in support of the POSIX application environment.
REXX/VM- (REstructed eXtended eXecutor programming language) processes English-like commands.
XEDIT- A full-screen editing facility that runs under CMS.
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References
CMS Command and Utility Reference. Manual Number: SC24-6010-02. Third Edition (May 2002).
CMS User’s Guide. Manual Number: SC24-6009-00. First Edition (July 2001).