How can you monitor a running SMART test?

• A. smartctl -a /dev/sdX
• B. smartctl -c /dev/sdX (capabilities & progress).
• C. smartctl -l error /dev/sdX
• D. smartctl -t status /dev/sdX

Answer: (B)

Monitoring a running SMART test hinges on asking the drive for its current test status and how far the test has progressed. The capability query smartctl -c /dev/sdX is designed to report the device's SMART capabilities and, crucially, the progress of any running self-tests. With this view you can see that a test is in progress and estimate completion time based on the reported progress, without initiating a new test. The other options either return broader SMART data without a clear progress indicator, show only error logs, or correspond to commands that won't directly report ongoing test progress. Therefore, querying capabilities and progress with smartctl -c /dev/sdX is the most direct way to monitor a running SMART test. After starting a test, you can repeatedly run this to track how far along the test has gone and know when it finishes.