Examkin

Question

Difficulty: MediumResilience, High Availability, and Redundancy

A security administrator is troubleshooting a critical network storage appliance in a data center. The appliance features dual internal power supply units (PSUs) to ensure hardware fault tolerance. However, during a recent scheduled power maintenance event on a single electrical circuit, the appliance unexpectedly lost power and shut down. Investigation reveals that both PSUs were plugged into the same rack Power Distribution Unit (PDU). Which of the following infrastructure modifications should the administrator implement to prevent single-circuit power outages from taking the appliance offline?

  1. A
    Configure the storage disks in a RAID 1 mirroring array across dual disk controllers.
  2. Connect each power supply unit to separate, independent Power Distribution Units (PDUs) fed by distinct power sources.Answer
  3. C
    Set up asynchronous storage replication to a secondary off-site facility to lower the Recovery Point Objective (RPO).
  4. D
    Implement NIC teaming in active-passive mode across the appliance's redundant network interfaces.

Answer

Connect each power supply unit to separate, independent Power Distribution Units (PDUs) fed by distinct power sources.
Connecting each redundant power supply unit to a separate, independent Power Distribution Unit fed by distinct power lines eliminates single points of failure in the electrical distribution path. If one PDU or utility feed goes offline, the second PSU continues to draw power from the remaining active PDU, allowing the appliance to operate without interruption.

Step-by-Step Solution

1
Analyze the root cause of the system outage described in the scenario.
The system shut down because both redundant power supplies were plugged into the same PDU, making that PDU and its single circuit a single point of failure.
Redundant hardware components inside a chassis cannot provide high availability if they rely on a single shared upstream power source.
2
Identify the appropriate architectural modification for power redundancy.
Each power supply unit must be connected to independent PDUs backed by separate electrical circuits or Uninterruptible Power Supply (UPS) feeds.
A dual-bus power configuration ensures continuous server operation even if an entire PDU or electrical breaker trips.

Key Concept

Power Redundancy and Single Points of Failure
Estimated Time:1m 15s
Rate this question

Topics

Resilience, High Availability, and Redundancy

More questions from this topic