HP storageworks HSG80 Reference Manual page 214

Glossary
DDL
Dual data link. The ability to operate on the CI bus using both paths simultaneously to the
same remote node.
device
In its physical form, a magnetic disk that can be attached to a SCSI bus. The term is also used
to indicate a physical device that has been made part of a controller configuration; that is, a
physical device that is known to the controller. Units (virtual disks) can be created from
devices, once the devices have been made known to the controller.
The targets, initiators, hubs, converters, adapters, and similar items interconnected to form a
SCSI bus. Connectors, expanders, and hubs do not use a SCSI bus ID. See also node;
peripheral device.
differential I/O module
A 16-bit I/O module with SCSI bus converter circuitry for extending a differential SCSI bus.
See also I/O module.
differential SCSI bus
A bus in which a signal level is determined by the potential difference between two wires. A
differential bus is more robust and less subject to electrical noise than is a single-ended bus.
DILX
Disk Inline Exerciser. DILX is a diagnostic used to test the data transfer capabilities of disk
drives in a way that simulates a high level of user activity.
DIMM
Dual Inline Memory Module.
dirty data
The write-back cached data that has not been written to storage media, even though the host
operation processing the data has completed.
disaster tolerance
The ability to resume data center operations shortly after a significant event occurs at the
primary data center. The ability to restart processing can require an alternate data center, with
current copies of critical data in a usable state.
disk inline exerciser
See DILX
Glossary–6 HSG80 Array Controller V8.7 Command Line Interface Reference Guide