Open System Services Management and Operations Guide (G06.25+, H06.03+)

Glossary
Open System Services Management and Operations Guide—527191-002
Glossary-2
DSV
the software product number and rrr is the base version identifier (such as G01) or
software product revision (SPR) identifier (such as AAB.)
DSV. See distribution subvolume (DSV).
Epoch. The period beginning January 1, 1970, at 0 hours, 0 minutes, and 0 seconds
Coordinated Universal Time (UTC). See also Coordinated Universal Time (UTC).
FIFO. A type of special file that is always read and written in a first-in, first-out manner.
file. An object to which data can be written or from which data can be read. A file has
attributes such as access permissions and a file type. In the OSS environment, file
types include regular file, character special file, block special file, FIFO, and directory.
filename. In the OSS environment, a component of a pathname containing any valid
characters other than a slash (/) or a null. In the Guardian environment, a filename is
the set of node name, volume name, subvolume name, and file identifier characters
that uniquely identifies a file.
fileset. In the OSS environment, a set of files with a common mount point within the file
hierarchy. A fileset can be part or all of a single virtual file system.
On an HP NonStop S-series or NonStop NS-series system, the Guardian file system
for a node has a mount point and is a subset of the OSS virtual file system. The entire
Guardian file system therefore could be viewed as a single fileset. However, each
volume, and each process of subtype 30, within the Guardian file system is actually a
separate fileset.
The term “file system” is often used interchangeably with “fileset” in UNIX
documentation.
file system. In the OSS environment, a collection of files and file attributes. A file system
provides the namespace for the file serial numbers that uniquely identify its files. Open
System Services provides a file system (see also ISO/IEC IS 9945-1: 1990 [ANSI/IEEE
Std. 1003.1-1990], Clause 2.2.2.38); the Guardian application program interface (API)
provides a file system; and OSS Network File System (NFS) provides a file system.
(OSS NFS filenames and pathnames are governed by slightly different rules than OSS
filenames and pathnames.) Within the OSS and OSS NFS file systems, filesets exist
as manageable objects.
On an HP NonStop S-series or NonStop NS-series system, the Guardian file system
for a node is a subset of the OSS virtual file system. Traditionally, the API for file
access in the Guardian environment is referred to as the “Guardian file system.”
In some UNIX and NFS implementations, the term “file system” is used to mean the
same thing as “fileset.” That is, a file system is a logical grouping of files that, except
for the root of the file system, can be contained only by directories within the file
system. See also fileset.
free list. The list of available inodes that can be allocated to files.