NonStop S-Series Hardware Installation and FastPath Guide (G06.25+)

Glossary

HP NonStop S-Series Hardware Installation and FastPath Guide—529443-001

Glossary-25

directory entry

directory entry. In the Open System Services (OSS) file system, an object that associates

a filename with a file. Several directory entries can associate names with the same file.

See also link.

directory loop. In the Open System Services (OSS) file system, an error condition in which

a directory is identified as its own parent directory.

directory special file. See directory.

directory stream. In the Open System Services (OSS) file system, an object with an

opaque data type. A process can sequentially read directory entries from a directory

stream.

directory tree. A hierarchy of directories. In the Open System Services (OSS) environment,

directories are connected to each other in a branching hierarchical fashion such that

only one path exists between any two directories (if no backtracking occurs).

disconnecting means. A device, group of devices, or other means by which the conductors

of a circuit can be disconnected from their source of supply.

discovery. For the OSM and TSM client software, the process of identifying the resources

that exist on an HP NonStop™ server. See also incremental discovery and initial

discovery.

disk bootstrap. A software entity residing on disk that is used to load the HP NonStop™

operating system image (OSIMAGE) into memory during a system load. A disk that

contains the disk bootstrap is referred to as a bootable disk. The disk bootstrap is

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 magnetic disk. Random access to

addressable locations on a magnetic disk is provided by magnetic read/write heads.