easyMultiple Choice
CV0-004 Practice Question: A systems administrator needs to apply a critical…
A systems administrator needs to apply a critical security patch to a set of application servers running in a cloud environment. The administrator wants to minimize downtime and ensure that if the patch causes issues, the servers can be rolled back quickly. Which of the following is the BEST approach?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use a blue-green deployment, patch the green environment, then switch traffic.
Blue-green deployment allows zero-downtime patching by switching traffic from the current (blue) environment to the patched (green) environment, and if issues occur, traffic can be switched back instantly, providing immediate rollback. Option A is incorrect because patching all servers at once causes downtime and no quick rollback. Option B is incorrect because taking snapshots before patching and restoring if needed incurs downtime during restore and is not as quick as switching traffic. Option C is incorrect because using an automated configuration management tool to apply patches gradually may not provide instant rollback and could still cause partial downtime.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Patch all servers at once during a maintenance window.
Why it's wrong here
Patching every server simultaneously maximises blast radius: a faulty patch breaks the whole fleet at once with no healthy capacity to serve traffic, and rollback must still be performed everywhere. It suits environments tolerating full outage, not one requiring minimal downtime and quick recovery.
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Take a snapshot of each server, apply the patch, and if issues occur, restore from snapshot.
Why it's wrong here
Snapshots capture disk state but restoring one requires stopping the instance, replacing the volume and rebooting, producing downtime per server. The scenario demands minimal downtime plus fast rollback, which image-based redeployment of a replacement instance satisfies. Snapshots suit data-recovery points rather than rapid application rollback.
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Use an automated configuration management tool to apply the patch gradually.
Why it's wrong here
Configuration management applies patches consistently but offers no rollback mechanism for a faulty patch; reverting requires redeploying the prior configuration state, which is slower than restoring a captured image. It suits maintaining drift-free, repeatable configuration across fleets, not rapid recovery from a bad patch.
- ✓
Use a blue-green deployment, patch the green environment, then switch traffic.
Why this is correct
Blue-green deployment keeps the current blue environment serving traffic while the green environment is patched and validated. Switching traffic only after verification, and reverting by redirecting back to blue, satisfies the stem's requirements for minimal downtime and rapid rollback.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CV0-004 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CV0-004 exam.