HP NetServer AA 6200 Solution Release 3.0 Administrator's Guide

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Chapter 2 HP NetServer AA Overview
In addition to the concepts described in Chapter 1, the fault tolerant technology coordinates all
I/O requests and responses between the CEs and IOPs using the ESIs and the IL, as shown in
Figure 2-1.
• In the server, the ESIs (Endurance System Interconnects) provide the interconnect paths
for all server I/O requests and responses. These paths connect the IOPs to the CEs as
follows:
- ESI11 is the path from IOP1 to CE1.
- ESI12 is the path from IOP1 to CE2.
- ESI21 is the path from IOP2 to CE1.
- ESI22 is the path from IOP2 to CE2.
• The IL (IOP Link) is a dedicated private network for completing mirror copies
(transferring mirrored disk data) between the IOPs, and for communication between the
IOPs. The IL is physically supported by connecting two Ethernet adapters, one in each
IOP.
Figure 2-1 Interconnect Paths in the HP NetServer AA Server
CE 1
CE 2
IOP 1 IOP 2
The ESI is the I/O data path
between the CE and
redirected devices on the
IOPs.
Local Area Network
IOP 1 IOP 2
The IL is the mirror
copy data path between
the IOPs.
CE 2CE 1
CE 2CE 1
IOP 1
IOP 2