CompTIA Server+ SK0-005 Practice Question

Hardware RAID controllers disable write-back caching when the backup cache (BBU) is missing, discharged, or has failed. With write-through caching enforced, every write must commit to disk before the next I/O begins, dramatically reducing throughput even though the disks themselves are healthy. Sector errors, partition alignment issues, or a corrupt filesystem table can harm performance, but none would automatically force the controller to switch its cache policy to write-through. Therefore, a cache battery failure best matches the symptoms.