Dot Hill Systems SANnet II 200 - Manual (Page 31)

fast write Allows disk write commands to be safely acknowledged to the host before the data is
actually written to the disk media. This can be enabled/disabled through the storage
management software.
fast/wide SCSI Data transfer rate of 20 MB/sec. Wide devices can be connected to a standard SCSI
interface but the extra data lines need to be terminated.
fault tolerance The capacity to cope with internal hardware problems without interrupting the array's data
availability, often by using backup systems brought online when a failure is detected.
Many arrays provide fault tolerance by using RAID architecture to give protection against
loss of data when a single disk drive fails. Using RAID 1 (mirroring), RAID 3 or 5
(striping with parity), or RAID 6 or 1+0 (mirroring and striping) techniques, the array
controller can reconstruct data from a failed drive and write it to a standby or replacement
drive.
fault tolerant
logical drive A logical drive that provides protection of data in the event of a single drive failure by
employing RAID 1, 3, 5, or 6 (also known as RAID 1+0).
FC-AL Fibre Channel-Arbitrated Loop. FC-AL is implemented as either a loop or a Fabric. A
loop can contain up to 126 nodes, accessible through only one or two servers.
fibre channel A cost-effective gigabit communications link deployed across a wide range of hardware.
fibre channel
HBAs Fibre channel adapters of a host computer, server, or workstation.
fibre hubs An Arbitrated Loop Hub is a wiring concentrator. "Arbitrated" means that all nodes
communicating over this Fibre loop are sharing a 100MBps segment. Whenever more
devices are added to a single segment, the bandwidth available to each node is further
divided. A loop configuration allows different devices in the loop to be configured in a
token ring style. With a Fibre Hub, a Fibre loop can be re-arranged in a star-like
configuration for the Hub itself contains port bypass circuitry that forms an internal loop
inside. Bypass circuits can automatically reconfigure the loop once a device is removed or
added without disrupting the physical connection to other devices.
FRU Field-Replaceable Unit
full-duplex Data transmission in both directions at the same time. See also half-duplex and simplex.
GB Gigabyte. 1,000,000,000 (one billion) bytes.
GBIC Gigabit Interface Converter. A hot-swappable input/output device that plugs into a Gigabit
Ethernet port or Fibre Channel.
groups A group is a new data object that allows multiple servers to be contained under a single
category, are similar in concept to domains, and allow you to organize servers within
SANscape. Instead of a linear tree of all the managed servers, the SANscape operator can
organize the servers into like sets or groups. In the case where many servers are present,
groups allow more icons to appear at the same time in the main SANscape window
without scrolling. Groups are not required. You can configure SANscape for no groups
and fifteen servers, for example, or for one group with ten servers underneath, with an
additional five at the top level. SANscape allows any combination. The number of groups
permitted and the number of servers within a group is limited only by available array
memory. If a server is a member of a group and a user deletes that group from the group
list box, SANscape reassigns the servers in that group to the no group category. SANscape
automatically remaps the tree in the main window.
half-duplex Refers to an interface, such as SCSI, that can transmit data in only one direction at a time.
See also full-duplex and simplex.
HBA Host Bus Adapter
host bus adapter A card that connects a peripheral device to the computer system's I/O bus.
hot plug The ability to remove, replace, or add a device while current I/O processes continue.
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