HP Data Protector A.06.11 Recovery Manual page 163

Dbobject
DC directory
DCBF
delta backup
device
device chain
device group
device streaming
(Informix Server specific term) An Informix Server physical
database object. It can be a blobspace, dbspace, or logical
log file.
The Detail Catalog (DC) directory contains DC binary files,
which store information about file versions. It represents the
DCBF part of the IDB, which occupies approximately 80% of
the IDB. The default DC directory is called the dcbf directory
and is located on the Cell Manager in the directory
Data_Protector_program_data\db40 (Windows Server
2008), Data_Protector_home\db40 (other Windows
systems), or /var/opt/omni/server/db40 (UNIX systems).
You can create more DC directories and use a custom location.
Up to 50 DC directories are supported per cell. The default
maximum size of a DC directory is 16 GB.
The Detail Catalog Binary Files (DCBF) part of the IDB stores
information about file versions and attributes. It occupies
approximately 80% of the IDB. One DC binary file is created
for each Data Protector medium used for backup. Its maximum
size is limited by the file system settings.
A delta backup is a backup containing all the changes made
to the database from the last backup of any type.
See also backup types.
A physical unit which contains either just a drive or a more
complex unit such as a library.
A device chain consists of several standalone devices configured
for sequential use. When a medium in one device gets full, the
backup automatically continues on a medium in the next device
in the device chain.
(EMC Symmetrix specific term) A logical unit representing several
EMC Symmetrix devices. A device cannot belong to more than
a single device group. All devices in a device group must be
on the same EMC Symmetrix unit. You can use a device group
to identify and work with a subset of the available EMC
Symmetrix devices.
A device is streaming if it can feed enough data to the medium
to keep it moving forward continuously. Otherwise, the tape
has to be stopped, the device waits for more data, reverses the
Disaster recovery guide 163