NonStop System Glossary

open file
In the Open System Services (OSS) file system, a file with a file descriptor.
open file description
In the Open System Services (OSS) file system, a data structure within a NonStop Expand node
that contains information about the access of a process or of a group of processes to a file. An
open file description records such attributes as the file offset, file status, and file access modes. An
open file description is associated with only one open file but can be associated with one or more
file descriptors.
open migration
In the Open System Services (OSS) file system, the set of events and outcomes that occur when an
open file description is inherited by a child process in a different processor than its parent process.
Contrast with open propagation.
open propagation
In the Open System Services (OSS) file system, the set of events and outcomes that occur when an
open file description is inherited by a child process in the same processor as its parent process.
Contrast with open migration.
Open SCSI
A subsystem that provides the hardware and software for a SCSI-2 open interface that runs on
NonStop S-series servers and to which developers can attach small computer system interface
(SCSI).
open system
A system with interfaces that conform to international computing standards and therefore appear
the same regardless of the system’s manufacturer. For example, the Open System Services (OSS)
environment on NonStop systems conforms to international standards such as ISO/IEC IS
9945-1:1990 (ANSI/IEEE Std. 1003.1-1990, also known as POSIX.1), national standards such
as FIPS 151-2, and portions of industry specifications such as the X/Open Portability Guide Version
4 (XPG4).
Open System Services (OSS)
An open system environment available for interactive or programmatic use with the NonStop
operating system. Processes that run in the OSS environment usually use the OSS application
program interface. Interactive users of the OSS environment usually use the OSS shell for their
command interpreter. Synonymous with Open System Services (OSS) environment. Contrast with
Guardian.
Open System Services (OSS) environment
The NonStop Open System Services (OSS) application program interface (API), tools, and utilities.
Open System Services (OSS) Monitor
A Guardian utility that accepts commands affecting OSS objects through an interactive Guardian
interface named the Subsystem Control Facility (SCF).
Open System Services (OSS) signal
A signal model defined in the POSIX.1 specification and available to processes in the OSS
environment. OSS signals can be sent between processes.
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