After replacing a failed drive in a hardware RAID-6 virtual disk, the controller automatically begins rebuilding the array. Within minutes, users report that file shares and virtual machines hosted on the same storage are unbearably slow. The administrator must keep the array protected but wants production I/O to take precedence over the rebuild task. Which RAID-controller setting should be lowered to reduce the rebuild's impact on foreground traffic while still allowing the rebuild to finish?
Lower the controller's rebuild rate (rebuild priority) setting.
Start a background initialization of the virtual disk.
Change the cache policy from write-back to write-through.
Most hardware RAID controllers expose a rebuild rate (sometimes called rebuild priority or reconstruction rate) that specifies what percentage of controller and disk resources are allotted to an array rebuild. Reducing this value throttles the rebuild so the controller can devote more bandwidth to user read/write requests, improving perceived performance at the cost of a longer rebuild window.
Changing the stripe size would require destroying and recreating the logical drive-it cannot be altered online and does not influence resource allocation during a rebuild. Switching the cache policy from write-back to write-through affects how write data is committed to disk but leaves rebuild scheduling unchanged. Forcing a background initialization applies to newly created virtual disks; starting that task would add, not subtract, background workload. Therefore, adjusting the rebuild rate is the correct action.