Psu Redundancy And Population Rules - Dell EMC PowerEdge MX7000 Field Service Manual

Table 23. MX7000 population rules (continued)
Category Maximum population
Only one type of IOM can be offered in Fabric-C (Fibre Channel or SAS IOM, not mixed).
Only one type of switch can be offered in Fabric-B (HPCC or Ethernet).
Two Fabric-C SAS IOMs must be installed if the enclosure contains a Storage Node.
Mix Speed of pass-through in same fabric is not enabled.
Mezzanine If the enclosure contains a storage node, Fabric-C MiniMezzanine card (HBA330 or Jumbo PERC) must be
cards installed in one compute node.
Dual Port or quad port mezzanine cards must be installed for redundant IOM/Pass-through configurations.
The second processor must be installed on the compute node to support Fabric-B Mezzanine / IOM and
Fabric-C Mezzanine / IOM.

PSU redundancy and population rules

The number of PSUs required depends on the enclosure configuration and redundancy required. The minimum requirement is
two PSUs. The enclosure supports one of the following redundancy modes:
● No redundancy: This mode distributes the enclosure power load across all PSUs. There are no specific PSU population
requirements for No redundancy. The intent of this mode is to have the highest possible limit for power enablement of
devices that are added to the enclosure. If there are single or multiple PSU failures, then the enclosure limits performance to
operate within the power capabilities of the remaining PSUs.
● Grid redundancy: This mode distributes the enclosure power load across all PSUs. The six PSUs are organized into two
groups: Grid A consisting of PSUs 1, 2, 3, and Grid B consists of PSUs 4, 5, 6. For grid redundancy, PSUs should be
populated in the following order: 1, 4, 2, 5, 3, 6. The grid with the largest PSU capacity determines the limit for power
enablement of devices that are added to the enclosure. If there is a grid or PSU failure, then the enclosure power is
distributed among the remaining PSUs with the intent that a single healthy grid will continue to provide power to all the
components in the system which can experience varied performance depending on the workload.
● PSU redundancy: This mode distributes the enclosure power load across all PSUs. There are no specific PSU population
requirements for PSU redundancy. PSU redundancy is optimized for a population of six PSUs, and the enclosure limits the
power enablement of devices to fit within five PSUs. If there is a single PSU failure, then the enclosure power is distributed
among the remaining PSUs to provide power to all the components in the system which can experience varied performance
depending on the workload. If there are fewer than six PSUs, then the enclosure limits the power enablement of devices
to fit within all populated PSUs. If there is a single PSU failure, then the enclosure limits performance to operate within the
power capabilities of the remaining PSUs.
Table 24. PSU population rules
Hot Spare: The MX7000 PSUs support the Hot Spare feature with three PSU pairs. This feature enables a PSU pair to have
one active PSU and one PSU in sleep mode while the enclosure power consumption is low, and the three PSU pairs meet all the
power requirements for the enclosure. This enables efficient power utilization when the overall enclosure power requirement is
low. The partner PSU wakes the paired PSU from sleep mode by sending a WAKE signal when the enclosure power requirement
increases. The PSU pairs for MX7000 are—1 & 4, 2 & 5, and 3 & 6.
74 Technical specifications
PSU count
2
3
4
5
6
Population order
1, 4 (Optimized for Grid Redundancy 1+1, and Hot Spare)
1, 4, 2, 5 (Optimized for Grid Redundancy 2+2, and Hot Spare)
1, 4, 2, 5, 3, 6 (Optimized for Grid Redundancy 3+3, PSU
Redundancy 5+1, and Hot Spare)
1, 4, 2
1, 4, 2, 5, 3