The loud noises from the servers are most likely caused by failing hard disk drives, which can produce clicking or grinding sounds. Replacing the drives with new ones can prevent data loss and downtime. Replacing the drives can be done without shutting down the server if they are hot-swappable, which means they can be removed and inserted while the server is running. References: CompTIA Server+ Certification Exam Objectives, Domain 3.0: Storage, Objective 3.1: Given a scenario, install, deploy, configure and update physical storage devices.