A server contains a 3 disk RAID 5 array. The red LED is illuminated on one of the drives. Which of the following should the server administrator perform?

A red LED on a drive in a RAID array typically signifies that the drive has failed or is in a critical state. In a 3-disk RAID 5 array, one drive can fail without data loss due to parity, but it enters a degraded state. The failed drive must be replaced to rebuild the array and restore full redundancy.

Restoring the drive from backup is not the correct action when a physical drive has failed; the failed drive needs to be physically replaced first, and then the RAID controller will rebuild the data onto the new drive using the parity information from the remaining drives, not from an external backup.

Rebooting the server will not fix a physically failed drive and might even complicate the array's recovery process or prevent the system from booting if the RAID controller cannot properly handle the degraded state during startup.

Reconfiguring RAID 5 to RAID 10 is a major change that would require significant downtime, data migration, and potentially more drives, and it is not the appropriate immediate response to a single failed drive.