Course Description

This course is designed to provide a detailed look at the various components, data structures and mechanisms used to implement the OpenVMS operating system. Topics include memory management and Files-11. The materials will include SDA displays from live systems and kernel mode programs, in addition to the usual flow descriptions and data structure diagrams.

Who Should Attend

OpenVMS System Programmers

Prerequisites

To get the most from this course, students should have:

• Completion of OpenVMS Academy Programming Features - course code VM310
• Completion of OpenVMS Alpha Internals I - course code U3719S
• Completion of OpenVMS Alpha Internals II - course code U3720S
• Read and ideally write code, in VAX macro.
• Ability to program in DEC C.

Benefits of Attending this Class

The primary objective of the course is to give the system programmer a living big picture of the operating characteristics and the interrelationships of the major OpenVMS subsystems. The majority of code will be presented in the C language and will be current as of Version 8.3 of OpenVMS.

The class uses the System Dump Analyzer on a live system to examine the data structures that form the operating system. The dynamics of the operating system will be explored through changes to data structures visible through SDA. The focus is on the three major subsystems of OpenVMS:

• Process and Scheduling
• Memory Management
• I/O

Course Contents

Image activation

• Memory Management Concepts
• The Process Header
• Image Activation
• Image Activation and Paging
• Clustering on Pagefault Reads

Process paging dynamics and structures

• Evolution of a Page Table Entry
• Sections
• The Working Set List
• The PFN Database
• The Free Page List
• The Modified Page List
• Page Files
• Page File Internal Support
• Swapper Related Activities

Global paging

• Shared Images and Global Sections
• Global Section Dynamics
• Shareable Image Issues
• Fixup Sections
• OpenVMS Alpha Shareable Images
• Known Files
• The System Header

Memory Management: "Big Picture" Review

• Three-Level Address Translations
• Image Activation
• Making a Page Valid
• A Page on the Free or Modified
• Page List Page File Interval Support
• A Page No Longer In Memory
• Swapping Related Structures
• The System Header
• Working Set Slots

Files-11

• Files-11 Concepts
• File Header
• The Files-11 Reserved Files

XQP Switches

• The Extended QIO Procedures
• File Open Related
• Data Structures
• Data Structures Relateing to Mounted Volumes
• Contiguity and the File System
• File System Caching Parameters