HP NetServer AA 4000, Installation Manual

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Preparing for the Installation 1-3
Figure 1-1 Sample Endurance Hardware Configuration
Device Redirection
Because all I/O devices in the 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.
IOP
CE
Tuple 2
To the network
IL cable
Tuple 1
IOP
CE
MIC cable
MIC cable