User's Guide

 There are two power redundancy modes, or N+N redundant and N+1 redundant mode.

 In the N+N redundant mode, each power unit is divided into two groups to configure the

redundant power supply system. If a power supply in a group is defected, only the power of

the other group can maintain the system operation.

 In the N+1 redundant mode, power units are not groped but each power unit is controlled

individually. Using a power supply in addition to the number of power units required for the

normal system operation enables redundant power system.

 The power control policy includes three modes, or CPU performance, “maintain redundancy” and

“recover redundancy” modes.

 The CPU performance mode makes the EM card prioritize the operation performance of CPU

blades. In this mode, if the EM card cannot accept a new power request from a CPU blade

with the power redundancy maintained, the EM card releases the power redundant

configuration and permits the new power request from the CPU blade. (If a power unit is

defected during operation under the release of the power redundant configuration, then the

system may be forcibly shut down.)

 The “maintain redundancy” mode makes the EM card accept a new power request from a

CPU blade within the range allowing the power redundancy to be maintained. If the EM card

cannot accept a new power request from a CPU blade with the power redundancy maintained,

the EM card denies the request. In the “maintain redundancy” mode, any measures is not

taken if the power redundancy is lost due to an event such as a failure of a power unit. (When

a power unit is defected further in no power redundancy status, the system may be shut down

forcibly.)

 The “recover redundancy” mode makes the EM card accept a new power request from a CPU

blade within the range allowing the power redundancy to be maintained and limit the

operation performance of CPU blades to suppress the power consumption for recovery of the

power redundancy if the redundancy is lost due to an event such as a failure of a power unit.

(Depending on operations of CPU blades, the EM card cannot reduce the power consumption

to the value allowing the power redundancy to be recovered.) When a switch module inserted

to a switch module slot issues a power-on request, the EM card checks the power consumption

of the switch module and turns on the power of the switch module if the power-on is possible

within the maximum power consumption management described above.

When a switch module, which is inserted to a switch module slot, issues a power-on request, the

EM card checks the power consumption often switch module and turns on the power of the switch

module if the power-on is possible within the maximum power consumption management

described above.

When a CPU blade inserted to a CPU blade slot requests the permission of using power, the EM

card permits the CPU blade to use the power if the power consumption is possible within the

maximum power consumption management described above.

TIPS:

A CPU blade subject to power-on issues the permission of using power to the EM card. The

power is not turned on if the EM card does not permit the CPU blade to use the power due to an

event such as power shortage.