What does a non-zero Reallocated_Sector Count mean?

• A. Unreadable sectors waiting for remap
• B. Media damage — drive deteriorating
• C. Drive is healthy
• D. Severe media damage or unreadable blocks

Answer: (B)

The main idea is that Reallocated_Sector Count tracks how many sectors the drive has had to replace because they were unreadable or bad. When this value is non-zero, it means the drive has already encountered bad sectors and remapped them to spare locations, which points to physical media damage and ongoing deterioration. That’s why it signals a health issue rather than a healthy drive. It isn’t describing unreadable sectors that are merely waiting to be remapped (that would be a pending or current pending counter), and it’s not accurate to call a drive healthy when this count has already increased. In short, any non-zero reallocation indicates some level of media wear, so back up data and monitor or plan for replacement as the count rises.