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

Glossary
HP NonStop S-Series Hardware Installation and FastPath Guide—529443-001
Glossary-14
cluster switch
cluster switch. See HP NonStop™ Cluster Switch (model 6770) and HP NonStop™
ServerNet Switch (model 6780).
cluster switch enclosure. An enclosure provided by HP for housing the subcomponents of
an HP NonStop™ Cluster Switch. The subcomponents include the ServerNet II Switch,
the AC transfer switch, and the uninterruptible power supply (UPS). A cluster switch
enclosure resembles, but is half the height of, a standard HP NonStop S-series system
enclosure.
cluster switch group. Within an external ServerNet fabric, all the cluster switches that
belong to the same cluster switch zone. A cluster switch group can consist of up to four
6780 switches, each representing one cluster switch layer. All of the cluster switches
that form a cluster switch group typically are installed in the same cluster switch rack.
cluster switch layer. The topological cluster switch position within a cluster switch group.
Each cluster switch group can contain up to four layers, numbered 1 to 4 from bottom
to top. A cluster switch layer consists of a pair of cluster switches (X and Y) and
provides connections for up to eight ServerNet nodes. Layers within a group are
interconnected by intragroup cables. When all four layers are present, the intragroup
cables are configured as a vertical tetrahedron. See also cluster switch layer number.
cluster switch layer number. A number in the range 1 through 4 that identifies the position
of a cluster switch within a cluster switch group. See also cluster switch group.
cluster switch logic board. A circuit board that provides switching logic for the HP
NonStop™ ServerNet Switch (model 6780). The logic board (LB) has a front panel for
operator and maintenance functions and is a Class-3 CRU.
cluster switch rack. A mechanical frame consisting of or based on a 19-inch rack that
supports the hardware necessary for a cluster switch group.
cluster switch zone. A pair of X-fabric and Y-fabric cluster switch groups and the ServerNet
nodes connected to them. Up to three zones are possible. The zones, if more than
one, are interconnected by interzone cables, with each cluster switch layer cabled
separately from the other layers.
CME. See correctable memory error (CME).
CMI. See Communications Management Interface (CMI).
code file. See object code file.
code segment. A segment that contains executable instructions of a program or library to
be executed plus related information. Code segments can be executed and also
accessed as read-only data but not written to by an application program. These read-
only and execute-only segments are efficiently shared among simultaneous executions
of that program or library. Therefore, they are read from disk but are never written back
to disk. See also TNS code space.