HP MSA 1040 HP MSA Events Description Reference Guide (762785-001, March 2014) - Page 75

DSD Drive spin down. A power-saving feature that monitors disk activity in the storage system and spins down inactive disks based on user-selectable policies. dual-port disk A disk that is connected to both controllers so it has two data paths, achieving fault tolerance. Dynamic Host See DHCP. Configuration Protocol dynamic spare An available compatible disk that is automatically assigned, if the dynamic spares option is enabled, to replace a failed disk in a vdisk with a fault-tolerant RAID level. See also available disk, compatible disk, dedicated spare, and global spare. EC Expander Controller. A processor (located in the SAS expander in each controller module and expansion module) that controls the SAS expander and provides SES functionality. See also EMP, MC, and SC. EMP Enclosure management processor. An EC subsystem that provides SES data such as temperature, power supply and fan status, and the presence or absence of disks. enclosure A physical storage device that contains I/O modules, disk drives, and other FRUs. enclosure management See EMP. processor Expander Controller See EC. expansion enclosure See drive enclosure. expansion module A FRU that contains the following subsystems and devices: a SAS expander and EC processor; host, expansion, and service ports; and midplane connectivity. In a drive enclosure, the upper expansion module is designated A and the lower one is designated B. explicit mapping Access settings for a host to a volume that override the volume's default mapping. See also default mapping and masking. extrinsic methods Methods which are particular to a specific class in SMI-S. See also intrinsic methods. failback See recovery. failover In an active-active configuration, failover is the act of temporarily transferring ownership of controller resources from an offline controller to its partner controller, which remains operational. The resources include volumes, cache data, host ID information, and LUNs and WWNs. See recovery. FC Fibre Channel interface protocol. FC-AL Fibre Channel Arbitrated Loop. The FC topology in which devices are connected in a one-way loop. FDE Full disk encryption. A method by which you can secure the data residing on a system. See also lock key, passphrase, and repurpose. Fibre Channel Arbitrated Loop See FC-AL. field-programmable gate array See FPGA. field-replaceable unit See FRU. FPGA Field-programmable gate array. An integrated circuit designed to be configured after manufacturing. FRU Field-replaceable unit. A part that can be removed and replaced by the user or support technician without having to send the product to a repair facility. full disk encryption See FDE. global spare A compatible disk that is reserved for use by any vdisk with a fault-tolerant RAID level to replace a failed disk. See also available disk, compatible disk, dedicated spare, and dynamic spare. HBA Host bus adapter. A device that facilitates I/O processing and physical connectivity between a host and the storage system. Glossary 75