CompTIA Server+ SK0-005 Practice Question
A Linux database server uses a PCIe hardware RAID controller with a battery-backed write cache to manage a six-disk RAID 10 array. Over the past hour users complain that write operations are extremely slow. The administrator runs iostat and sees average write latency has climbed from 5 ms to more than 150 ms, and the controller's management utility logs repeatedly state:
Adapter 0: Battery status - Failed; switching logical drives to Write-Through
Which of the following is the MOST likely cause of the sudden performance degradation?
The RAID controller's cache battery has failed, causing the controller to disable write-back caching.
The storage backplane has partially failed and is forcing the array to operate on a single SAS channel.
The file system has less than 1 % free space, so writes are fragmenting and slowing down.
The array is rebuilding because the disks are mismatched in size, leading to extended parity calculations.