HP Surestore Disk Array 12h - And FC60, Advanced User'S Manual, Page: 446 / 466

446
25 MB/s (quarter speed), or 12.5 MB/s (eighth speed) over distances of up to 100 m over
copper media, or up to 10 km over optical links. The disk array operates at full speed.
Fibre Channel Arbitrated Loop (FC-AL)
One of three existing Fibre Channel topologies in which two to 126 ports are
interconnected serially in a single loop circuit. Access to the FC-AL is controlled by an
arbitration scheme. The FC-AL topology supports all classes of service and guarantees
in-order delivery of Fibre Channel frames when the originator and responder are on the
same FC-AL. The disk array’s default topology is arbitrated loop.
Fibre Channel Arbitrated Loop Hub
A full-duplex, 1.063 Gb/s intelligent hub used in an FC-AL topology to increase the
loop’s reliability, the number of loop connections, and the distances between the host
system(s) and disk array(s). A maximum of ten devices can be connected to each FC-AL
hub.
Fibre Channel Protocol for SCSI (FCP)
FCP defines a high-level Fibre Channel mapping layer (FC-4) using lower-level Fibre
Channel (FC-PH) services to transmit SCSI command, data, and status information
between a SCSI initiator and a SCSI target across the Fibre Channel link using Fibre
Channel frame and sequence formats.
flushing cache
The process of writing the contents of write cache memory to a disk. Flushing occurs at
regular intervals during normal operation, and when power to the disk array is
interrupted.
foreign controller
Any controller other than the last one to complete the Start-Of-Day process in a given
slot. At the completion of the SOD process, the identification of the controller is stored.
If a different controller is installed in the slot, it is considered foreign. See resident
controller.