NonStop S-Series Hardware Installation and FastPath Guide (G06.26+)

Glossary
HP NonStop S-Series Hardware Installation and FastPath Guide—529876-001
Glossary-13
chassis
chassis. A single sheet-metal structure that holds all the other components of an enclosure.
See also enclosure.
checksum. A generic term, meaning to add together (although the definition of add need
not be a normal arithmetic add) all of the data to produce a check word. See also cyclic
redundancy check (CRC).
child process. A process created by another process. The creating process becomes the
parent process of the new process. See also parent process.
CIIN. A command file in the SYSnn subvolume that is read and executed by the startup HP
Tandem Advanced Command Language (TACL) process after system load if the CIIN
file is specified in the CONFTEXT file and enabled in the OSM or TSM Low-Level Link.
circuit breaker. A device designed to open and close a circuit by nonautomatic means and
to open the circuit automatically on a predetermined overcurrent without damage to
itself.
CISC compiler. See TNS compiler.
CISC processor. An instruction processing unit (IPU) that is based on complex
instruction-set computing (CISC) architecture.
class. A group of object-oriented data entities and the methods associated with that group.
Class-1 CRU. A customer-replaceable unit (CRU) that probably will not cause a partial or
total system outage if the documented replacement procedure is not followed correctly.
Customers replacing Class-1 CRUs are not required to have previous experience
replacing HP NonStop™ S-series CRUs. However, for some CRUs, customers must
be able to use the tools needed for the replacement procedure (which are common
tools) and must protect components from electrostatic discharge (ESD).
Class-2 CRU. A customer-replaceable unit (CRU) that might cause a partial or total system
outage if the documented replacement procedure is not followed correctly. Customers
replacing Class-2 CRUs should have either three or more months of experience
replacing HP NonStop™ S-series CRUs or equivalent training. Customers must be
able to use the tools needed for the replacement procedure and must protect
components from electrostatic discharge (ESD).
Class-3 CRU. A customer-replaceable unit (CRU) that probably will cause a partial or total
system outage if the documented replacement procedure is not followed correctly.
Customers replacing Class-3 CRUs should have either six or more months of
experience replacing HP NonStop™ S-series CRUs or equivalent training. Customers
must be able to use the tools needed for the replacement procedure, must protect
components from electrostatic discharge (ESD), and must understand the
dependencies involved in NonStop S-series CRU-replacement procedures, such as
disk-path switching. Replacement by a service provider trained by HP is
recommended.