A Study of Software Failures and Recovery in the MVS Operating System

This paper describes an analysis of system detected software errors on the MVS operating system at the Center for Information Technology (CIT), Stanford University. The analysis procedure demonstrates a methodology by which systems with automatic recovery features can be evaluated. Most common error categories are determined and related to the program in execution at the time of the error. The severity of the error is measured by evaluating the criticality of the program for continued system operation. The system recovery and error correction features are then analyzed and an estimate of the system fault tolerance to errors of different levels of severity is made.