A+ Lesson

RAID Failure Indicators for A+

Last updated: 6/10/2026

Short answer

Support-level idea: RAID introduces an additional failure layer. Multiple drive failures, controller faults, or corrupted RAID metadata can cause the array to be degraded or disappear. The technician must identify array-level messages and avoid making changes that could worsen recovery chances. Primary actions include documenting messages, preserving configuration where possible, and escalating to RAID administration or vendor support when rebuild/metadata repair is required.

Why it appears on the exam

- Given a scenario with multiple bay LEDs and controller 'array missing' messages, select the correct immediate support action (document and escalate vs. rebuild now). - Distinguish between degraded array (logical volume present) and array missing (logical volume absent) and choose appropriate triage steps.

Key concepts

Concept 1

Required terms

RAID failure: A condition where a RAID volume or its redundancy has been compromised, potentially resulting from multiple drive failures, controller issues, or corrupted RAID metadata. degraded array: A RAID array that has lost redundancy (one or more drives failed or removed) but still presents the logical volume. array missing: A RAID controller or OS condition where the logical RAID volume is no longer presented to the operating system.

Example

A controller utility reports 'degraded' after a single drive failure: identify redundancy lost and plan replacement with rebuild.

Concept 2

How RAID Failure Indicators works

Support-level idea: RAID introduces an additional failure layer. Multiple drive failures, controller faults, or corrupted RAID metadata can cause the array to be degraded or disappear. The technician must identify array-level messages and avoid making changes that could worsen recovery chances. Primary actions include documenting messages, preserving configuration where possible, and escalating to RAID administration or vendor support when rebuild/metadata repair is required.

Example

Multiple bay LEDs and 'array missing' in controller after a power surge: do not reinitialize the controller; escalate and document symptoms.

Concept 3

Common confusion

Technicians may attempt to rebuild or reinitialize arrays without understanding the impact on metadata; such actions can make recovery harder. Another mistake is treating array missing as a single-disk swap-array-level expertise is required.

Example

A controller utility reports 'degraded' after a single drive failure: identify redundancy lost and plan replacement with rebuild.

Concept 4

Core 1 (220-1201) question cues

Given a scenario with multiple bay LEDs and controller 'array missing' messages, select the correct immediate support action (document and escalate vs. rebuild now); Distinguish between degraded array (logical volume present) and array missing (logical volume absent) and choose appropriate triage steps.

Example

Multiple bay LEDs and 'array missing' in controller after a power surge: do not reinitialize the controller; escalate and document symptoms.

Sample questions

Select an answer to reveal the explanation. For tracked practice and weak-area review, use the Cultiv8 app.

Q1.A technician is troubleshooting this situation: A controller utility reports 'degraded' after a single drive failure: identify redundancy lost and plan replacement with rebuild. What should they identify?

Q2.A support ticket includes this clue: Multiple bay LEDs and 'array missing' in controller after a power surge: do not reinitialize the controller; escalate and document symptoms. Which concept is being tested?

Q3.Read this A+ scenario: Multiple bay LEDs and 'array missing' in controller after a power surge: do not reinitialize the controller; escalate and document symptoms. Which term or action matches it?

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