Ethernet Adapter Installation and Support Guide

Glossary
Ethernet Adapter Installation and Support Guide—425684-003
Glossary-23
disk cache
placed on the disk either as part of a tape load or as a result of the SCF CONTROL
DISK, REPLACEBOOT command.
disk cache. A temporary storage buffer into which data is read, retained, and perhaps
updated before being written to disk, for more efficient processing.
disk drive. A device that stores and accesses data on a disk. There are two types of disk
drives: magnetic and optical. Random access to addressable locations on a magnetic
disk is provided by magnetic read/write heads. Random access to addressable
locations on an optical disk is provided by a low-intensity laser. See also volume.
DISKGEN. A system generation option that invokes the DISKGEN program to copy directly
to disk those files necessary to generate a HP NonStop™ Kernel operating system.
DISKGEN can be used instead of a system image tape (SIT).
DISK object type. The Subsystem Control Facility (SCF) object type for all disk devices
attached to your system.
disk volume. See volume.
distributed system. A system that consists of a group of connected, cooperating
computers.
Distributed Systems Management (DSM). A set of tools used to manage HP NonStop™
S-series systems and Expand networks.
Distributed Systems Management/Software Configuration Manager (DSM/SCM). A
graphical user interface (GUI)-based program that installs new software and creates a
new HP NonStop™ Kernel operating system. DSM/SCM creates a new software
revision and activates the new software on the target system.
distribution subvolume (DSV). A subvolume containing program files for a particular
software product along with the software release version update (RVU) document
(softdoc) file for that product. The format for a DSV name is Ynnnnrrr or Rnnnnrrr,
where nnnn is the software product number and rrr is the base version identifier
(such as D20) or software product revision (SPR) identifier (such as AAB).
DLC. See data link control (DLC).
DNS. See Domain Name System (DNS).
DNS server. A server that resolves hostnames to Internet protocol (IP) address mapping
queries. These queries originate from either client computers, which are known as
resolvers, or other Domain Name System (DNS)
servers, which accounts for the
distributed nature of DNS. See also Network Information Service (NIS)
.
domain. (1) A set of objects over which control or ownership is maintained. Types of
domains include power domains and service processor (SP) domains. (2) In the