What is SYS1.UADS for?

Have you ever thought what would happen if your External Security Manager (RACF, ACF2, or TSS) becomes unavailable? How will you be able to access your mainframe system? Well, SYS1.UADS is the answer to this question. This dataset contains the list of users that can access the mainframe system should […]


RACF Utilities Summary

IBM provides several utilities for RACF that can be helpful for a mainframe security administrator. Without going into much detail on each of the RACF utilities, the following table provides an explanation of what each of these utilities is for: Utility Description IRRMIN00 RACF database initialisation utility. IRRMIN00 can be […]


What is SAF?

SAF or System Authorisation Facility is an interface defined by MVS that enables programs to use system authorisation services to control access to resources, such as datasets, MVS commands, JES, etc. SAF can either process security authorisation requests directly, or work with an External Security Manager (ESM) such as RACF, […]


z/OS In-Built Security Features

The following are the in-built security features that come with z/OS: System Authorization Facility (SAF): SAF is part of the operating system. SAF is available whether or not an additional security product such as RACF, ACF2 or Top Secret is installed. If an additional security product is installed, SAF routes […]


RACF Templates

The RACF database contains records whose format is controlled by a set of database templates. The templates map out how profiles are written on the RACF database. IBM makes changes to the templates to add new segments to the RACF database, or to add new fields to existing segments. The […]