A+ RAID 0, 1, 5 and 10: fault tolerance versus capacity
RAID combines drives for different capacity, performance, and availability goals. RAID 0 has no redundancy. A two-drive RAID 1 mirror can survive one member failure. RAID 5 uses distributed parity, while RAID 10 stripes across mirrors. The array design changes which failures are tolerable. None of these arrangements prevents authorized deletion or guarantees a clean recovery from ransomware.
How to read the scenario
Read the failure pattern and usable-capacity requirement. Keep independent backups even when the array can tolerate a drive failure.
Identify the required outcome, the evidence already provided, and the limits on the technician’s action. Compare every option against those details before deciding. Record why the closest alternative does not meet the stated need.
Original practice example
A user compares a two-drive RAID 1 mirror with a single drive. Which TWO statements about the mirror are correct? Select TWO.
- It doubles usable capacity compared with either member.
- It prevents accidental file deletion.
- It still needs an independent backup.
- It can remain available after one member fails.
Show the answer and explanation
It still needs an independent backup.; It can remain available after one member fails.
A two-drive mirror tolerates one member failure, but deletions and corruption can affect both copies, so an independent backup remains necessary.
Study questions
Which objective does this guide support?
220-1201, objective 3.4. This independent guide supports original practice and does not replace the full official objectives.
What should I watch for in a scenario?
Read the failure pattern and usable-capacity requirement. Keep independent backups even when the array can tolerate a drive failure.
Source and version
CompTIA official 220-1201 objectives, objective 3.4. Verified November 5, 2026. Use the exam code when choosing study materials; similarly named certifications can have different objectives.