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Avoid using zip ties to bundle cables, instead use velcro hook-and-loop ties that do
not have hard edges, and can be removed without cutting. Fastening cables with
velcro ties also reduces the impact of gravity on the bend radius.
Note:
Gravity decreases the bend radius and results in the loss of light (fiber
optic), signal power, and quality.
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For overhead cable supports:
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Ensure that the supports are anchored adequately to withstand the significant
weight of bundled cables. Anchor cables to the overhead supports, then again
to the rack to add a second point of support.
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Do not let cables sag through gaps in the supports. Gravity can stretch and
damage cables over time. You can anchor cables to the rack with velcro ties at
the mid-point of the cables to protect your cable bundles from sagging.
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Place drop points in the supports that allow cables to reach racks without
bending or pulling.
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If the cable is running from overhead supports or from underneath a raised floor,
be sure to include vertical distances when calculating necessary cable lengths.
Ensure airflow
Bundled cables can obstruct the movement of conditioned air around the cluster.
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Secure cables away from fans.
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To keep conditioned air from escaping through cable holes, employ flooring seals
or grommets.
Prepare for maintenance
To accommodate future work on the cluster, design the cable infrastructure. Think
ahead to required tasks on the cluster, such as locating specific pathways or
connections, isolating a network fault, or adding and removing nodes and switches.
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Label both ends of every cable to denote the node or switch to which it should
connect.
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Leave a service loop of cable behind nodes. Service technicians should be able to
slide a node out of the rack without pulling on power or network connections. In
the case of Generation 6 nodes, you should be able to slide any of the four nodes
out of the chassis without disconnecting any cables from the other three nodes.
WARNING
If adequate service loops are not included during installation,
downtime might be required to add service loops later.
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Allow for future expansion without the need for tearing down portions of the
cluster.
Connect the internal cluster network
Internal network cables connect nodes to the cluster's internal network so the nodes
can communicate with each other.
Procedure
1. Depending on the type of internal network card in the node, connect a network
cable between the int-a port, the bottom of the two ports, and the network
switch for the Internal A network.
2. For the secondary internal network, connect the int-b port, the top port, to a
separate network switch for the int-b network.
Installation Guide
14
Generation 6 Installation Guide 0
