Users Guide
• Redundancy status and overall power health
Redundancy policies
Redundancy policy is a congurable set of properties that determine how CMC manages power to the chassis. The following redundancy
policies are congurable:
• Grid Redundancy
• No Redundancy
• Redundancy Alerting Only
Grid Redundancy policy
The Grid Redundancy policy is also knows as 1+1 policy, for one active and one spare PSU.
The purpose of the Grid Redundancy policy is to enable an enclosure system to operate in a mode in which the enclosure can tolerate AC
power failures. These failures may originate in the AC power grid, the cabling and delivery, or a Power Supply Unit (PSU) itself. When you
congure a system for Grid Redundancy, connect PSUs 1 and 2 to separate power grids.
In this mode, the CMC ensures that power usage is maintained such that the system continues to operate with no degradation if there is a
failure of either the grid or a single PSU. Server power-on is limited to the available power of a single PSU. If at any time redundancy cannot
be maintained (such as if a PSU is removed or fails) alerts are triggered, the chassis health becomes Critical.
No Redundancy policy
The No Redundancy policy is also known as 2+0 policy.
In this mode, all the power of both PSUs is available and used, but there is no assurance that a PSU or grid failure does not aect system
operation.
Redundancy Alerting Only policy
The Redundancy Alerting Only policy permits server power-on to use the capacity of both PSUs, while alerting on actual conditions such as
removal or failure of a PSU, or actual power consumption exceeding the capabilities of a single PSU. This is the default policy.
Fault Tolerant Redundancy
This policy uses the power capacity limits of a Single Power Supply Unit (PSU) similar to the Grid Redundancy policy. In this mode, the sub-
system peak power of the CPU is replaced with a new IccMax limit. This policy is applicable only to Dell's 14th generation of blade servers.
PSU failures
PSU failures of any type are always alerted, regardless of the selected redundancy policy.
NOTE
: Modify the modular enclosure Redundancy Policy while the enclosure is powered o.
150 Managing and monitoring power