HP StorageWorks 2000 Series Reference Manual page 307

enclosure
management
processor (EMP) An Expander Controller subsystem that provides data about an
enclosure's environmental conditions such as temperature, power
supply and fan status, and the presence or absence of disk drives.
Ethernet adapter An adapter that connects an intelligent device to an Ethernet network.
Usually called an Ethernet network interface card, or Ethernet NIC.
(SNIA)
Expander Controller
(EC) The processor (located in the SAS expander in each controller module
and expansion module) that is primarily responsible for enclosure
management and SES.
expansion module A FRU that contains: a SAS expander and Expander Controller
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.
fabric A Fibre Channel switch or two or more Fibre Channel switches
interconnected in such a way that data can be physically transmitted
between any two N_Ports on any of the switches. (SNIA)
fabric switch A fabric switch functions as a routing engine that actively directs data
transfer from source to destination and arbitrates every connection.
Bandwidth per node via a fabric switch remains constant when more
nodes are added.
failback See recovery.
failover In an active-active configuration, failover is the act of temporarily
transferring ownership of controller resources from a failed controller
to a surviving controller. The resources include virtual disks, cache
data, host ID information, and LUNs and WWNs. See also recovery.
fault tolerance The capacity to cope with internal hardware problems without
interrupting the system's data availability, often by using backup
systems brought online when a failure is detected. Many systems
provide fault tolerance by using RAID architecture to give protection
against loss of data when a single disk drive fails. Using RAID 1, 3, 5,
6, 10, or 50 techniques, the RAID controller can reconstruct data from
a failed disk drive and write it to a spare or replacement disk drive.