IBM eServer OpenPower 720, Technical Overview And Introduction

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OpenPower 720 Technical Overview and Introduction
3.1 Reliability, availability, and serviceability
Excellent quality and reliability are inherent in all aspects of the IBM
Sserver
OpenPower
design and manufacturing. The fundamental objective of the design approach is to minimize
outages. The RAS features help to ensure that the system operates when required, performs
reliably, and efficiently handles any failures that might occur. This is achieved using
capabilities provided by both the hardware and the operating system.
The OpenPower, as a POWER5 server, enhances the RAS capabilities implemented in
POWER4-based systems. RAS enhancements available on POWER5 servers are:
򐂰 Most firmware updates allow the system to remain operational.
򐂰
The ECC has been extended to inter-chip connections for the fabric and processor bus.
򐂰 Partial L2 cache deallocation is possible.
򐂰 The number of L3 cache line deletes improved from 2 to 10 for better self-healing
capability.
The following sections describe the concepts that form the basis of leadership RAS features
of IBM
Sserver
OpenPower systems in more detail.
3.1.1 Fault avoidance
The OpenPower systems are built on a quality-based design to keep errors from ever
happening. This design includes the following features:
򐂰 Reduced power consumption, cooler operating temperatures for increased reliability,
enabled by copper chip circuitry, silicon-on-insulator, and dynamic-clock-gating
򐂰 Mainframe-inspired components and technologies
3.1.2 First Failure Data Capture
If a problem should occur, the ability to correctly diagnose it is a fundamental requirement
upon which improved availability is based. The OpenPower 720 incorporates advanced
capability in start-up diagnostics and in run-time First Failure Data Capture (FDDC) based on
strategic error checkers built into the chips.
Any errors detected by the pervasive error checkers are captured into Fault Isolation
Registers (FIRs), which can be interrogated by the service processor (SP). The SP in the
OpenPower 720 has the capability to access system components using special purpose
service processor ports or by access to the error registers (Figure 3-1 on page 49).