Endurance Software - HP NetServer AA 6200 Administrator's Manual

Endurance Software

Endurance software integrates and synchronizes processing across four industry-standard
Pentium class systems. All components are capable of multiprocessing, forming a logical, fully
redundant, fault tolerant server. This results in the Windows operating system, all applications,
and the local area network logically perceiving the integrated systems in the Endurance server
as a standard Windows server. Endurance server software provides fault tolerant functionality,
including:
• Redundant processing environment. Using redundant CEs and memory, the Endurance
software performs CPU and memory functions in a tightly coupled manner. In the event of
a CPU or memory failure, the operating system remains continuously available, providing
constant computing without any loss of context.
• Redundant I/O subsystem. The Endurance software redirects I/O requests from the CE
to the IOPs. The Endurance software coordinates all I/O requests, as follows:
- Because all I/O devices in the Endurance server physically reside on the IOPs,
Endurance software redirects all I/O requests from the CEs to the IOPs. As a result,
these I/O devices are logically associated with the CE. For example, the Endurance
software can redirect a CD-ROM drive physically located in an IOP so that it is
logically assigned to the CE (the CE has complete control of that CD-ROM drive).
- For mirrored disk devices and redundant Ethernet connections, the Endurance
software coordinates all I/O processing so that these redundant components appear as
a single logical device. For example, in a mirrored disk set, the two physical disks
(one on each IOP) appear to the CE operating system and applications as one logical
disk. If a disk failure occurs, the disk operations can transparently continue operating
without affecting any server applications or clients.
• Automatic fault detection and reporting. The Endurance software continuously
monitors the server. If the software detects a fault, the Endurance server isolates the fault
and deconfigures any affected components. When a fault occurs, Endurance software
ensures that the server remains operational by automatically using the redundant
components. The fault detection and reporting process occurs seamlessly, and in a fully
operational Endurance server, it maintains complete server availability. The Endurance
software reports all events, including general status, state changes, and faults, to the
Windows event log or displays them in application windows as they occur. For a detailed
description of all Endurance messages, refer to
Introduction
HP Netserver AA Solution Messages.
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