ClearPath IX Systems Installation and Configuration Guide

Glossary
processing complex cabinet (PCC)
A single cabinet that can include one or two 2200 Series system instruction processors and
one or two main storage units completely independent from each other.
protocol
A set of rules or standards describing methods to achieve compatible transmission and
receipt of data (for example, message packets) over a network.
protocol port
The abstraction that transport protocols use to distinguish between multiple destinations
within a host computer. TCP/IP protocols identify ports using small positive integers.
Usually, the operating system allows an application program to specify which ports it
wants to use. Some ports are used for standard services (for example, electronic mail).
public network
A TCP/IP network that supports communication within the Internet at large. Hosts in a
public network must have globally unique IP addresses assigned by an Internet Registry.
Q
quorum
Voting mechanism used to guarantee that specific data necessary for recovery can be
maintained consistently between all cluster members.
quorum resource
A resource, accessible by all nodes of a cluster, that stores cluster management data such
as recovery logs for changes made to cluster data.
R
RAS
Abbreviation for reliability, availability, and serviceability.
RDMS 2200
See Relational Data Management System.
redundant array of independent disks (RAID)
(Originally, redundant array of inexpensive disks, or devices.) Multiple disk units
combined into a single logical device designed to increase data integrity and availability by
means of redundant copies of disk contents. Organization of the disks is defined by six
RAID levels—two of which (levels 1 and 5) are fault tolerant. In level 1 (disk mirroring)
disks are duplicated 100 percent on another disk for redundancy. In level 5 (striping with
parity) free space across multiple disks is combined into one logical volume and data is
spread in a fixed order across those disks (striping). Parity data saved with the striped
data allows information to be recreated if a disk should fail.
Relational Data Management System (RDMS 2200)
The Unisys relational data manager that provides a nonhierarchical database model.
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