How the system starts and manages batch jobs

December 11, 2010 Rui Miguel Feio

Batch processing is the most fundamental function of z/OS. Many batch jobs are run in parallel and JCL is used to control the operation of each job. Correct use of JCL parameters (especially the DISP parameter in DD statements) allows parallel, asynchronous execution of jobs that may need access to […]

System IPL Sequence

December 6, 2010 Rui Miguel Feio

The initialization process begins when the System Programmer or Operator selects the LOAD function at the Hardware Management Console (HMC). To successfully IPL z/OS, the system programmer needs to supply the following information: –    The device address of the IPL volume –    The LOADxx member that contains pointers to system […]

VTOC (Volume Table of Contents)

December 2, 2010 Rui Miguel Feio

z/OS uses a Catalog and a Volume Table of Contents (VTOC) on each DASD to manage the storage and placement of data sets The VTOC lists the data sets that reside on its volume, along with information about the location and size of each data set, and other data set […]

What is a Catalog?

December 1, 2010 Rui Miguel Feio

A catalog describes data set attributes and indicates the volumes on which a data set is located. When a data set is cataloged, it can be referred to by name without the user needing to specify where the data set is stored. Data sets can be cataloged, uncataloged, or recataloged. […]