For highest reliability, hot-swap fans should be implemented to maximize server up time. Recommended Required Recommended Any system that provides hot-swap power supply replacement and power supply redundancy should have local indicators that unambiguously indicate the supplies that must be replaced. These indicators guide service personnel to replace the correct power supply. Automatic retention mechanisms that prevent incorrect supply removal also satisfy this guideline. This section provides design guidelines for fault-tolerance features and capabilities.
Bus mastering is required for the drive controllers.
Use of multiple hard drives and controllers in a server system provides both performance and reliability benefits, therefore, it is recommended for server systems. The intelligent RAID controller may be internal to the server chassis, or within an external drive enclosure. If an intelligent RAID controller is provided in a system, it should be capable of handling sufficient amounts of disk storage to fulfill the needs of the targeted usage model for that server. These needs will vary based on the storage-intensive nature of the server's tasks. RAID 5 is also acceptable.