Rules For Achieving Redundancy - IBM x3850 X6 Planning And Implementation Manual

Four 900W
Four 1400W
Four 750W DC
There are two different 1400W power supply units available, a standard 1400W PSU and a
high altitude 1400W PSU. The high altitude PSU should be used when the server's location is
at an altitude higher than 5000 meters from sea level. It is not advised to mix the high altitude
PSUs with the standard 1400W or 900W PSUs, as this will nullify the high altitude
capabilities.
Table 4-4 shows the different power supply installation configurations, the policies, and the
level of redundancy achieved depending on the type and number of power supplies installed.
Table 4-4 Power supply installation and redundancy
Power Power
supply 1 supply 2
1400W 1400W
1400W 900W
900W 1400W
None 1400W
None None
900W 900W
None 900W
None None
750W DC 750W DC
a. Workload and configuration dependent. Use the IBM Power Configurator to plan for your level of redundancy:
http://ibm.com/systems/bladecenter/resources/powerconfig.html

4.5.3 Rules for achieving redundancy

In order to achieve power supply and power feed redundancy, observe the following rules:
Power supplies in bays 1 and 3 (Group A) and bays 2 and 4 (Group B) must be balanced
in both quantity and power output (A=B).
Power feeds to Group A and Group B must be different for redundancy. See Figure 4-3 on
page 116.
Mixed wattages must also be balanced on Group A (900W/1400W) and Group B
(900W/1400W).
IMM2 Code requires power supplies in bays 1 and 3 to be wired to feed 1, and power
supplies in bays 2 and 4 to be wired to feed 2. This is due to how the power supplies are
internally connected and how the IMM2 determines if the system is redundant based on
the policy selected. If the power supplies are not correctly connected, the selected IMM2
policy may not function as intended.
Power Power
supply 3 supply 4
1400W 1400W
900W 1400W
1400W 900W
1400W None
1400W None
900W 900W
900W None
900W None
750W DC 750W DC
Fully Power
redundant module
AC source redundant
Yes Yes
a
Yes No
a
Yes No
a
Yes No
No No
a
Yes Yes
a
Yes No
No No
a
Yes Yes
Chapter 4. Infrastructure planning
Non-
redundant
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
115