NonStop System Glossary

DSV
See distribution subvolume (DSV).
DTE
See data terminal equipment (DTE).
dual inline memory module (DIMM)
Small circuit boards carrying memory integrated circuits, with signal and power pins on both sides
of the board. A DIMM is different from a single inline memory module (SIMM) in that the connections
on each side of the module connect to different chips, whereas the connections on both sides of
a SIMM connect to the same memory chip. This difference gives the DIMM a wider data path, as
more modules can be accessed at once.
dual-ported
The capability of a ServerNet adapter or peripheral device to receive data and commands from
two sources although only one source might have access at any particular moment.
duplex
Having two active processor elements, each contained in a separate NonStop Blade Element, per
logical processor. Also called dual-modular redundancy (DMR).
duplicate file descriptor
In the Open System Services (OSS) file system, a file descriptor that refers to the same open file
description as another file descriptor.
DWARF
See Debug With Arbitrary Record Format (DWARF).
dynamic configuration file (DCF)
An attachment file that is produced by the client software for OSM and TSM and accompanied
by an incident report. The DCF contains a snapshot of the system configuration, the state of the
NonStop server, and outstanding alarms at the time that the incident report was issued. The DCF
is used by the service provider to avoid having to perform online discovery of the server over
dial-up telephone lines.
Dynamic Host Configuration Protocol (DHCP)
An Internet protocol for automating the configuration of computers that use TCP/IP. DHCP can
automatically assign IP addresses, deliver TCP/IP stack configuration parameters such as the subnet
mask and default router, and provide other configuration information such as the addresses for
printer, time, and news servers.
dynamic information
Information that represents the set of resources that actually exist in the current configuration of a
NonStop server. Dynamic information is gathered from a server through the process of discovery.
Contrast with static information.
dynamic-link library (DLL)
A collection of procedures whose code and data can be loaded and executed at any virtual
memory address, with run-time resolution of links to and from the main program and other
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