Glossary-3
Glossary
H
HBA (host bus adapter)
An HBA is the critical link between a host server or workstation
and a subsystem, integrating computing platforms, OSs, and I/O
protocols to ensure proper interoperability and functionality. The
bus adapter provides direct storage connectivity from the system
to data within the subsystem and enables stable, high-speed
transmission of information and files. HBAs manage the
controller-specific aspects of handling a storage driver interface
device implemented as a target driver, which supports mass
storage peripheral devices such as disks and tapes. A storage
driver interface is used to implement SCSI and other storage
device drivers. An HBA connects the storage subsystem to the host
computer and uses either fiber or copper media.
hot-swapping
Removing a component from a system and installing a new
component while the power is on, the system is running, and
without pausing I/O.
K
kill
In active-active mode, one controller can kill the other controller by
resetting it and taking it offline.
L
LUN (logical unit number)
The number assigned to a subdevice (logical unit) of a SCSI device.
Each SCSI device can contain up to eight subdevices numbered 0
through 7; however, most SCSI devices contain only one subdevice
(LUN 0).
LVD (low voltage differential)
LVD is a method of powering SCSI cables that will be formalized in
the SCSI-3 specifications. LVD uses less power than the current
differential drive (HVD), is less expensive, and allows for higher
speeds such as those of Ultra2 SCSI. LVD requires 3.3 volts (versus
5 volts for HVD).
DuraStor IUG.book Page 3 Wednesday, January 30, 2002 10:49 AM
