Overland Storage SnapSAN S1000 User Manual page 119

SnapSAN S1000 User Guide
Failback
Failback occurs when a path with a higher priority than the currently active path is
restored. In this case, I/O will "fail back" to the higher priority path once it is available again.
Failover
The ability to automatically substitute a working system or path for one which has failed.
Failover/Failback
A combination of Failover and Failback. When a preferred path becomes unavailable,
another path is used to route I/O until the preferred path is restored. In this case I/O will
"fail back" to the preferred path once it is available again.
FC-AL
Short for Fibre Channel Arbitrated Loop. An FC-AL is a Fibre Channel network in which up
to 126 systems and devices are connected in a loop topology, with each transmitter
connecting to the receiver of the device on its logical right. The Fibre Channel Arbitrated
Loop protocol used for transmission is different from Fibre Channel switched and point-to-
point protocols. Multiple FC-AL loops can be connected via a fabric switch to extend the
network.
Fibre Channel
Fibre Channel (FC) is a gigabit-speed network technology which transports SCSI commands
over Fibre Channel networks. Fibre Channel was primarily concerned with simplifying the
connections and increasing distances, but later designers added the goals of connecting SCSI
disk storage, providing higher speeds and far greater numbers of connected devices.
Firmware
Software stored in read-only memory (ROM) or programmable ROM (PROM). Firmware is
often responsible for the behavior of a system when it is first switched on.
FL_port
A Fabric Loop port within a Fibre Channel switch that is capable of Fibre Channel
Arbitrated Loop operations and is connected to one or more NL_Ports via a Fibre Channel
Arbitrated Loop. An FL_Port becomes a shared entry point for public NL_Port devices to a
Fibre Channel fabric. FL_Ports are intermediate ports in virtual point-to-point links
between end ports that do not reside on the same loop, for example NL_Port to FL_Port to
F_Port to N_Port through a single Fibre Channel fabric switch.
Front-end
See Back-end.
Gigabit Ethernet
Also known as GigE or GbE, this Ethernet standard uses a one Gigahertz (1000 Hz) clock
rate to move data.
HBA
Short for Host Bus Adapter. An HBA is an I/O adapter that sits between the host computer's
bus and the Fibre Channel loop and manages the transfer of information between the two
channels. In order to minimize the impact on host processor performance, the HBA performs
many low-level interface functions automatically or with minimal processor involvement.
10400310-003 01/2013
©2010-13 Overland Storage, Inc.
Glossary
GL-4
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