Dell Chassis Management Controller Version 3.0 for Dell EMC PowerEdge VRTX User's Guide

Server Slot Power Priority Settings

CMC allows you to set a power priority for each of the four server slots in an enclosure. The priority settings are 1 (highest) through 9 (lowest). These settings are assigned to slots in the chassis, and the priority of the slots is inherited by any server inserted in that slot. CMC uses slot priority to preferentially budget power to the highest priority servers in the enclosure.

According to the default server slot priority setting, power is equally apportioned to all slots. Changing the slot priorities allows administrators to prioritize the servers that are given preference for power allocations. If the more critical server modules are left at their default slot priority of 1, and the less critical server modules are changed to lower priority value of 2 or higher, the priority 1 server modules is powered on first. These higher priority servers get their maximum power allocation, while lower priority servers may be not be allocated enough power to run at their maximum performance or they may not even power on at all, depending on how low the system input power cap is set and the server power requirements.

If an administrator manually powers on the low priority server modules before the higher priority ones, then the low priority server modules are the first modules to have their power allocation lowered down to the minimum value, in order to accommodate the higher priority servers. Therefore, after the available power for allocation is exhausted, CMC reclaims power from lower or equal priority servers until they are at their minimum power level.