IBM BladeCenter HX5

Chapter 8. IBM BladeCenter HX5 383
Figure 8-13 Blade showing power sharing cap and location
8.3.2 BladeCenter H considerations
Blade server placement in a chassis is vitally important in balancing the power consumption
and ensuring reliability. This section is only relevant if you use a BladeCenter H chassis. If you
use a BladeCenter S, this section does not apply.
For maximum redundancy, IBM always recommends that you install all four power supplies in
every H chassis. In the BladeCenter H, this configuration is important due to power domains.
In a BladeCenter H, you have two separate power domains:
򐂰 Domain 1: Blades 1 - 7
򐂰 Domain 2: Blades 8 - 14
With four power supplies, each domain has a redundant pair of power supplies. Not having
two power supplies for each domain can cause a loss of blades if the single power supply or
its power source fails. If the blades do not power off, they might throttle the processor speed
down to a point at which performance is severely degraded.
To determine the current power consumption, use the AMM. Move the blades around until the
maximum balance is obtained. Figure 8-14 on page 384 shows the location of the Power
Management menu in the AMM.
IBM MAX5
Power
sharing
cap
Blade server
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Blade server
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