Specifications

GL–23
Compaq HSG80 Array Controller ACS Version 8.4 Configuration and CLI Reference Guide
Ultra SCSI A Fast-20 SCSI bus. See also Wide Ultra SCSI.
unit A container made accessible to a host. A unit may be created from a single disk
drive or tape drive. A unit may also be created from a more complex container
such as a RAIDset. The controller supports a maximum of eight units on each
target.
See also target and target ID number.
unwritten cached
data
Sometimes called unflushed data.
See dirty data.
UPS Uninterruptible power supply. A battery-powered power supply guaranteed to
provide power to an electrical device in the event of an unexpected interruption to
the primary power supply. Uninterruptible power supplies are usually rated by the
amount of voltage supplied and the length of time the voltage is supplied.
VHDCI Very high-density-cable interface. A 68-pin interface. Required for
Ultra-SCSI connections.
virtual terminal A software path from an operator terminal on the host to the controller’s CLI
interface, sometimes called a host console. The path can be established via the
host port on the controller (using HSZterm) or via the maintenance port through an
intermediary host.
VTDPY An abbreviation for Virtual Terminal Display Utility.
warm swap A device replacement method that allows the complete system remains online
during device removal or insertion. The system bus may be halted, or quiesced,
for a brief period of time during the warm-swap procedure.
Wide Ultra SCSI Fast/20 on a Wide SCSI bus.
Worldwide name A unique 64-bit number assigned to a subsystem by the Institute of Electrical and
Electronics Engineers (IEEE) and set by DIGITAL manufacturing prior to shipping.
This name is referred to as the node ID within the CLI.