Hitachi Lighting 9900 Series Architecture Manual page 64

DD
Disk Director.
Data Duplication
Software that duplicates data as in remote copy or Point-in-Time (PiT) snapshots.
Data duplication is differentiated from data migration in that with data duplication at
the end of the process there are two copies of data and with data migration there is
only one.
Data Migration
Software that migrates data from one storage device to another. This feature is different
from data duplication in that at the end of the process there is only one copy of data.
Disaster Recovery
Disaster Recovery is the profession that plans to avoid disasters and to restore services
after a disaster. The level of preparedness to respond to an interruption in services by
implementing a disaster recovery plan to restore an organization's critical business
functions.
Downtime
A planned or unplanned interruption in system availability. Planned downtime is
usually for scheduled system maintenance and unplanned downtime usually includes
business interruptions or disasters. See also Business Interruptions, Disaster Recovery,
Business Continuity Planning (BCP), and Availability.
DR
Disaster Recovery.
DRR
Data Recovery and Regeneration.
DSS
Decision Support Systems is a term that refers to computer systems used in the areas
of business intelligence such as data warehousing, data mining, OLAP, and others.
DTA
Data Adapter.
ECC
Error correction code.
Glossary
55