VSAM Tutorial

Tutorials Library VSAM Introduction


VSAM Stands for Virtual Storage Access Method. VSAM is a data access method which is introduced in 1970’s. VSAM is the first access method that efficiently uses the storage and modifies only the data that exists on direct access storage device. The latest version of VSAM released in 1991 called VSAM 3.3 which contains enhancements like variable length support for RRDS and added DFSMS facilities.

VSAM can store and access the data from the files in the form of records. VSAM is an access method in the mainframe operating system and enables access to data on disk, tape or other external devices.


Readers who are having or not having mainframe knowledge.


The tutorial is intended for the readers with a little mainframe experience as the tutorial mainly focuses on how it is used in mainframe environment. In the tutorial, all the topics are covered with in depth description and can understandable by anyone who had minimum computation background.


Need to learn COBOL, JCL languages if learning the VSAM for processing files from COBOL programs.

Learn COBOL tutorial at COBOL Tutorial

Learn JCL tutorial at JCL Tutorial

There are no prerequisites to learn VSAM only for File storage structure, processing etc in mainframe. Having the computation background will be an advantage in understanding the concepts a bit easy. Without having computation background, it is a bit time taking to understand the concepts and need to go through the topic more than once to understand clearly.

Table of contents:

  1. VSAM - Introduction
  2. VSAM - Dataset Types
  3. VSAM - VSAM Struture
  4. VSAM - Cluster components
  5. VSAM - VSAM Creating utility
  6. VSAM - File status codes

Tutorials Library VSAM Introduction