Managing cables

Virtual Storage Platform F350, F370 Hardware Reference Guide

Version
88-08-0x
Audience
anonymous
Part Number
MK-97HM85016-07

Organize cables to protect the integrity of your connections and allow proper airflow around your storage system.

Cable lengths

The following table specifies the maximum length of SAS cables can be used to connect controllers and drive trays.

System

Maximum length

VSP F350

130 m or less

(426.5 ft or less)

VSP F370

150 meters or less

(492.13 ft or less)

Observing bend radius values

Never bend cables beyond their recommended bend radius. The following table provides general guidelines for minimum bend radius values, but you should consult the recommendation of your cable manufacturer.

Cable type

Minimum bend radius values

Fibre Channel

40 mm (1.73 inch)

iSCSI optical

40 mm (1.73 inch)

Category 5 Ethernet

Four times the outside diameter of the cable

SAS

40 mm (1.73 inch)

Protecting cables

Damage to the cables can affect the performance of your storage system. Observe the following guidelines to protect the cables:

  • Keep cables away from sharp edges or metal corners.
  • When bundling cables, do not pinch or constrict the cables.
  • Do not use zip ties to bundle cables. Instead, use Velcro hook-and-loop ties that do not have hard edges and which you can remove without cutting.
  • Never bundle network cables with power cables. If network and power cables are not bundled separately, electromagnetic interference (EMI) can affect your data stream.
  • If you run cables from overhead supports or from below a raised floor, include vertical distances when calculating necessary cable lengths.
  • If you use overhead cable supports:
    • Verify that your supports are anchored adequately to withstand the weight of bundled cables.
    • Gravity can stretch and damage cables over time. Therefore, do not allow cables to sag through gaps in your supports.
    • Place drop points in your supports that permit cables to reach racks without bending or pulling.
  • Unintentional unplugging or unseating of a power cable can have a serious impact on the operation of an enterprise storage system. Unlike data cables, power connectors do not have built-in retention mechanisms to prevent this from happening.

    To prevent accidental unplugging or unseating of power cables, the storage system includes a rubber cable-retention strap near the AC receptacle on each controller. These straps, shown in the following image, loop around the neck of a power cable connector, and the notched tail is slipped over the hook of the restraining bar fixed to the storage system.



Cabling full-width modules

When cabling full-width modules, route the cables horizontally, so that they do not interfere when replacing a module.

Ensuring adequate airflow
Bundled cables can obstruct the movement of conditioned air around your storage system.
  • Secure cables away from fans.
  • Keep cables away from the intake holes at the front of the storage system.
  • Use flooring seals or grommets to keep conditioned air from escaping through cable holes.
Preparing for future maintenance
Design your cable infrastructure to accommodate future work on the storage system. Give thought to future tasks that will be performed on the storage system, such as locating specific pathways or connections, isolating a fault, or adding or removing components.
  • Purchase colored cables or apply colored tags.
  • Label both ends of every cable to denote the port to which it connects.