“HA” to “hung”

HA

(n.) high availability.

HA data service

See data service.

halfword acknowledgment

(n.) On the SBus, an acknowledgment to indicate that the slave has read or written a halfword of data from the most-significant halfword of the data lines. If the transfer size is greater than a halfword, the master initiating the transfer can perform bus sizing.

halt

(v.) To intentionally stop the system from running; for example, in preparation for turning off the power.

handle

(n.) See grab handle.

handler

(n.) A routine that directs a simple condition, such as moving data.

hang

(v.) To cease operation because either an unexpected condition is not satisfied or an infinite loop is occurring. See also crash.

hard limit

(n.) For disk quotas, a maximum limit on file system resources (blocks) and inodes) that users cannot exceed.

hard link

(n.) A directory entry that references a file on disk. More than one such directory entry can reference the same physical file.

hashing

(n.) In managing databases, the process of changing a key ID value to an index value, with the intent of reducing search time.

HBA

See host bus adapter.

header file

The file at the top of a program that defines data types and sets variables used in the program.

heartbeat

(n.) In a Sun^TM Cluster configuration, a periodic message sent across all available cluster interconnect transport paths. Lack of a heartbeat after a specified interval and number of retries might trigger an internal failover of transport communication to another path. Failure of all paths to a cluster member results in the Cluster Membership Monitor reevaluating the cluster quorum.

hidden file

(n.) A special type of file, such as .login, that does not display in normal file listings. Hiding protects the file from deletion, modification, or unauthorized access. Special files usually pertain to system configuration.

hierarchy

(n.) A classification of relationships in which each item except the top one (called the root) is a specialized form of the item above it. Each item can have one or more items below it in the hierarchy. In the Java^TM class hierarchy, the root is the Object class.

home directory

(n.) The directory that the system administrator assigns to you; usually the same as the login directory. Additional directories that you create stem from the home directory.

host

A machine that is accessible over a network.

host bus adapter

(HBA) (n.) A controller board that connects the I/O expansion bus to the Small Computer System Interface (SCSI) subsystem.

host computer

(1) (n.) A computer system that is accessed by computer(s) and/or workstations at remote locations. Usually the host contains the data, but in networks, the remote locations can be “the host” and provide information to the network.

(2) (n.) In a multiple computer setting, the computer that emulates another computer.

host-resident fonts

(n.) The fonts stored on one system that are shared by a group of users of a particular printer. Host-resident fonts are usually different from printer-resident fonts, and are used less frequently.

hot-plugging

(n.) The process of adding or removing hardware devices while the system is running.

hot spot

(n.) In the X protocol, the point in a cursor that corresponds to the coordinates reported for the pointer.

hot-swappable

(adj.) Capable of enabling insertion or removal of a device while the computer is powered on and in operation.

HPC

(n.) high-performance computing.

HSM

(n.) hierarchical storage management.

hung

(adj.) Characteristic of a system that is frozen and unresponsive to commands.