g-26 McDATA® Sphereon 3032 and 3232 Fabric Switches Installation and Service Manual
Glossary

H

half duplex The capacity to transmit in two directions, but not simultaneously.
hardware Physical equipment (director, switch, or personal computer) as
opposed to computer programs or software.
Hardware Log Director or switch Hardware Log. Log displayed through the Product
Manager application that provides a history of FRU removals and
replacements (insertions) for an individual director or switch. The
information is useful to maintenance personnel for fault isolation and
repair verification. See also Audit Log; Event Log; Link Incident Log;
Threshold Alert Log.
HBA See host bus adapter.
Hertz Hz. A unit of frequency equal to one cycle per second.
heterogeneous fabric A fabric containing open-fabric-compliant products from various
vendors. Contrast with homogeneous fabric.
hexadecimal A numbering system with base of sixteen; valid numbers use the dig-
its 0 through 9 and characters A through F, where A represents 10 and
F represents 15 (D).
high availability A performance feature characterized by hardware component redun-
dancy and concurrent maintenance. High-availability systems maxi-
mize system uptime while providing superior reliability, availability,
and serviceability.
homogeneous fabric A fabric consisting of only one vendor’s products. Contrast with heter-
ogeneous fabric.
hop (1) Data transfer from one node to another node. (2) Describes the
number of switches that handle a data frame from its origination
point through it’s destination point.
hop count The number of hops a unit of information traverses in a fabric.
host bus adapter HBA. Logic card that provides a link between the server and storage
subsystem, and that integrates the operating systems and I/O proto-
cols to ensure interoperability.