Creating High-availability Power Solutions for the ProLiant ML570 Server

creating high-availability power solutions for the ProLiant ML570 server
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With the configuration illustrated in figure 1, an outage from power grid A (with the two
power supplies connected) would leave only one available power supply—not enough
to support a maximum configuration of the server. In this worst-case scenario, the server
would not only lose redundancy, but it might also lose availability.
To provide redundancy in the event one of the power grids fails, some customers may
decide to implement a dual-input PDU as illustrated in figure 2. A dual-input PDU
provides fast, automatic AC failover from one input source to the other in case of a
failure. If one of the power grids fails, the dual-input PDU will use the backup power grid
to supply power to the server. Refer to
www.compaq.com/products/servers/proliantstorage/power-protection/power-
distribution/dual_input_pdu/index.html for more information on the dual-input PDU.
figure 2: typical power supply configuration using a dual-input PDU in an environment with two
power grids
Power
Supply
Power
Supply
Power
Supply
ProLiant ML570 Server
Power Grid A Power Grid B
Dual Input PDU
Although this configuration appears to be an effective solution to provide server
redundancy, it creates another problem: this configuration creates a single point of
failure at the dual-input PDU. Failure of the dual-input PDU is unlikely, but a higher level
of redundancy can be achieved with a combination of PDUs.