ServerNet Cluster Manual

Planning for Installation

ServerNet Cluster Manual—520575-003

2-19

Locating the Servers and Cluster Switches

The servers must be located so that they can be connected to the cluster switches with

a 10-meter, 40-meter, or 80-meter cable. See Figure 2-6. This is not the straight-line

distance. Bends in the cable after it is installed can significantly reduce the actual

distance from the cluster switch to the server.

The cluster switches are packaged in separate enclosures or racks. HP recommends

that you do not install cluster switches adjacent to each other. (When cluster switches

are installed adjacent to each other, there is a higher potential for miscabling.).

For connections in a multilane link, you can use cables longer than 80 meters if certain

requirements are met. For details, see Table 2-4 on page 2-11. Figure 2-7 shows the

maximum cable lengths for a multilane link.

Figure 2-6. Maximum Cable Lengths for Servers and Switches

Caution. Do not exceed the 80-meter maximum cable length between a ServerNet node and

a cluster switch. Doing so can cause multiple, unrecoverable link failures to and from the node

that is in violation of the distance limit.

Figure 2-7. Maximum Cable Lengths With a Multilane Link

* 5 km cables can be used in a multilane link if the requirements in Table 2-4 on page 2-11 are met.

Group 01

80 m

160 m

Fiber-Optic

Cable

Fiber-Optic

Cable

80 m

Cluster Switch

VST038.vsd

Group 01

1.16 km *

80 m

Fiber-Optic

Cable

80 m

Fiber-Optic

Cable

VST079.vsd

Fiber-Optic

Cables

1 km

Cluster Switch

(X Fabric Shown)

This illustration uses four-lane links as an example. Two-lane links use lthe same maximum cable lengths.