ServerNet/FX Adapter Configuration and Management Manual

Glossary
ServerNet/FX Adapter Configuration and Management Manual—426872-002
Glossary-7
Passthrough modes
Passthrough modes. Hardware Passthrough: the ServerNet/FX adapter has power but is
not running operational microcode; it acts only as a hardware repeater. Packets pass
directly from one fiber-optic cable to another; they are regenerated but not reshaped or
resynchronized. Packets that travel though two or more hardware passthrough clusters
might be damaged. Physical Passthrough: same as hardware passthrough.
Software Passthrough: the ServerNet/FX adapter is running operational microcode,
but it cannot communicate with the cluster on which the it is resident. Packets coming
in from one fiber-optic cable are stored and then routed accordingly. The ServerNet/FX
adapter remains the physical neighbor of its left and right neighbors. Logical
Passthrough: A normal operating mode that allows two FOX nodes to communicate
by passing data through a fully operational intervening node. The ServerNet/FX
adapter is running operational microcode and can communicate with the cluster on
which it is resident.
path. The route between a processor and a subsystem. If a subsystem is configured for
fault tolerance, it has a primary path (from the primary processor) and a backup path
(from the backup processor).
Path down. A state in which a processor in a cluster on a FOX ring loses a FOX direct
logical path (XL, XR, YL, or YR) to a processor in another cluster on the FOX ring. See
also CPU stuck.
PMF CRU. See processor multifunction (PMF) CRU.
PRIMARY command. A sensitive SCF command that is used to toggle the primary and
backup processors of the FOX monitor process ($ZZFOX).
process. A program that has been submitted to the operating system for execution, or a
program that is currently running in the computer.
processor. (1) The central processing unit (CPU). A NonStop system has multiple
cooperating processors rather than a single CPU. Each processor reads program
instructions, moves data between processor memory and the ServerNet addressable
controllers (SACs), and performs arithmetic operations.
processor dump. A copy of the memory of a processor. A dump can be to disk or to tape.
processor enclosure. A NonStop S-series system enclosure containing exactly one group,
which includes processors, ServerNet adapters, disk drives, components related to the
ServerNet system area network (ServerNet SAN), and components related to electrical
power and cooling for the enclosure.
processor multifunction (PMF) CRU. A NonStop S-series customer-replaceable unit
(CRU) that contains a power supply, service processor (SP), ServerNet router,
Ethernet controller, three ServerNet addressable controllers (SACs), and a processor
and memory system in a single unit. The PMF CRU consists of three subassemblies:
the processor and memory board (PMB), the multifunction I/O board (MFIOB), and the
power supply subassembly.