On the Reliability of the IBM MVS/XA Operating System

Abstract
This paper describes an analysis of system-detected errors on the MVS operating system under the eXtended Architecture (XA) for two IBM 3081 systems. The analysis classifies the errors in categories and examines the effectiveness of the recovery system of the MVS/XA. Comparison of the results for the two IBM 3081's confirm the dependence of the error distribution on the type of system utilization. The results for one of the machines are compared to those obtained for the same system when operating under MVS/SP. The comparison of the MVS/XA to the MVS/SP reveals the following: more addressing errors, a better error recording system and improved reliability and fault tolerance.