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Glossary–12
HSG80 Array Controller V8.7 Command Line Interface Reference Guide
Glossary
half-duplex (adj)
Pertaining to a communications system in which data can be either transmitted or received but
only in one direction at one time.
hard address
The AL_PA which an NL_Port attempts to acquire during loop initialization.
heterogeneous host support
Also called noncooperating host support.
HIPPI–FC
Fibre Channel over HIPPI.
host
The primary or controlling computer to which a storage subsystem is attached.
host adapter
A device that connects a host system to a SCSI bus. The host adapter usually performs the
lowest layers of the SCSI protocol. This function may be logically and physically integrated
into the host system.
host compatibility mode
A setting used by the controller to provide optimal controller performance with specific
operating systems. This improves the controller performance and compatibility with the
specified operating system.
hot disks
A disk containing multiple hot spots. Hot disks occur when the workload is poorly distributed
across storage devices which prevents optimum subsystem performance. See also hot spots.
hot spots
A portion of a disk drive frequently accessed by the host. Because the data being accessed is
concentrated in one area, rather than spread across an array of disks providing parallel access,
I/O performance is significantly reduced. See also hot disks.
hot-pluggable
A replacement method that allows normal I/O activity on a device bus to remain active during
device removal and insertion. The device being removed or inserted is the only device that
cannot perform operations during this process. See also pluggable.