HP Rack and Power Manager User Guide

Overview
Configuration D
Figure 1-5 illustrates a redundant configuration in which servers with dual power supplies are
protected by multiple UPSs. The servers are both serially attached to different UPSs. One
server power supply is connected to a receptacle on the rear panel of each UPS. Each UPS is
connected to a separate power feed. The UPSs are monitored by a Management Server
located elsewhere on the network. Each server has an installed System Agent that receives
commands, such as displaying a pop-up message or shutting down the operating system, from
the Management Server. The servers also each have an installed Serial Relay Agent that is
used for communication between the UPS and the Management Server.
IMPORTANT: When planning a redundant configuration, consider that in normal operating
conditions, servers with multiple power supplies equally distribute the power load across each power
feed. A server with two power supplies applies 50% of the load to each power feed. In the event that
one power feed fails, the second power feed must be able to handle 100% of the load. Ensure that each
UPS in the redundant configuration can support the entire load in the event of a power failure.
Redundant UPS configurations should be tested thoroughly to ensure the load handling capabilities and
power fail settings of each UPS before an actual power failure event.
HP Rack and Power Manager User Guide 1-11
HP CONFIDENTIAL Codename: Swordfish Part Number: 311371-002 Last Saved On: 2/3/04 3:10 PM