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Systems & Data Center · Foundational

Redundant Power Supply

Two or more power supply units in a server, each able to carry the load alone so one can fail without downtime.

Definition

Redundant PSUs should connect to separate PDUs fed from different power sources (A and B feeds) to protect against circuit failure. They are usually hot-swappable.

Example

Each server's PSU1 connects to PDU-A and PSU2 to PDU-B.

Exam tip

Redundant PSUs on the same PDU or circuit do not protect against a circuit failure.

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