CompTIA Server+ (SK0-005)Server Hardware Installation and ManagementMedium

A server administrator needs to replace a failed power supply unit (PSU) in a production server. The server is equipped with redundant, hot-swappable PSUs. Which of the following is the MOST important safety precaution to take before physically removing the failed PSU?

  1. AVerify that the remaining PSU is fully functional and providing power.
  2. BGround yourself with an anti-static wrist strap.
  3. CEnsure the server is completely powered off and unplugged.
  4. DNotify all users that the server will experience a brief outage.
Show answer & explanation

Correct answer: A. Verify that the remaining PSU is fully functional and providing power.

Before removing a hot-swappable redundant PSU, it is critical to verify the operational status of the other PSU to ensure the server maintains uninterrupted power. Removing a PSU while the remaining one is also failed or not fully functional would cause the server to crash.

Why the other options are wrong

  • B. An anti-static wrist strap is general ESD safety, but verifying power redundancy is more critical for hot-swap operations.
  • C. The scenario specifies 'hot-swappable' PSUs, meaning the server should remain powered on.
  • D. While good practice, notifying users is not the MOST important safety precaution related to the physical removal of a hot-swappable PSU.

Hot-Swappable PSU Replacement

The process of replacing a power supply unit in a server while the server remains powered on and operational, relying on redundant power sources.

  • Requires redundant PSUs (N+1 or N+N).
  • Primary goal is to maintain server uptime.
  • Crucial to verify remaining PSU functionality before removal.

Memory trick: Before you 'swap', make sure the 'other' one is 'running'!

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