Compaq 124708-001 - ProLiant Cluster - 1850 White Paper page 6

ServerNet II PCI Adapter
ServerNet II Switch
TC000602WP
Doc Number
W P
HITE APER
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ServerNet II Hardware Components
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As shown in Figure 2, the basic hardware components for a cluster of two servers include
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ServerNet II PCI Adapters and ServerNet cables. Each ServerNet II PCI Adapter has two ports (X
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and Y). The respective X and Y ports on the adapters can be linked to create redundant
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connections. If either the X or Y connection should fail, data is seamlessly transferred by the other
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connection, thus improving reliability. ServerNet II also provides high reliability through self-
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checking built into the application-specific integrated circuits (ASICs) and hardware routing
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protocol. The hardware routing protocol ensures end-to-end, reliable data transfer.
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ServerNet II uses industry-standard 64-bit, 66-MHz PCI components that contain several features
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of the VI Architecture to move data efficiently. The link media for ServerNet II is the same
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physical media used by gigabit Ethernet and Fibre channel (Serial 1000Base-CX up to 25 meters).
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Links are bi-directional with speeds of 1.25 + 1.25 gigabits per second (Gb/s).
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Figure 2. Redundant, direct ServerNet II interconnect for a cluster of two servers.
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A ServerNet II switch is required for clusters of more than two servers. The ServerNet switch is a
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. . 2U (3.5-inch) high, 19 inch-wide, rack-mounted device with connections for twelve ServerNet
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cables. Figure 3 shows a SAN consisting of six servers connected to a ServerNet II switch. A
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second switch and cables can be added for increased fault tolerance. As more nodes and data paths
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are added to the cluster, the aggregate bandwidth of the ServerNet II interconnect increases.
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Multiple switches can be cascaded to support as much bandwidth as needed.
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Figure 3. Six-node cluster with redundant ServerNet II switches.
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