Enhanced I/O Subsystem Recovery and Availability on the IBM System z9

Overview

This paper presents an overview of recovery and how it interacts with other RAS functions - such as error-detection mechanisms in hardware, including automatic identification and recovery of failing elements - up to the point in time prior to the advent of the z9. It then presents the innovations to IOSS recovery and error detection in the z9 that further improve machine availability. The recovery infrastructure, which significantly reduces recovery time and makes recovery much less dependent on machine scaling for this and future generations of System z servers, is described.