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

Glossary
HP NonStop S-Series Hardware Installation and FastPath Guide—529876-001
Glossary-31
emitter-coupled logic (ECL) ServerNet cable
replaceable unit (CRU) that supports the emitter-coupled logic (ECL) interface. See
also emitter-coupled logic (ECL) and plug-in card (PIC).
emitter-coupled logic (ECL) ServerNet cable. A ServerNet cable that uses emitter-
coupled logic (ECL). Before the modular ServerNet expansion board (MSEB) was
introduced, ECL was the only ServerNet cable technology used by HP NonStop™
S-series servers. You can connect an ECL ServerNet cable directly to a ServerNet
expansion board (SEB) or to an MSEB using an ECL plug-in card (PIC).
empty directory. In the Open System Services (OSS) file system, a directory that contains
only an entry for itself and an entry for its parent directory.
empty string. In C and C++ programs, a character string that begins with a null character.
This term is synonymous with null string.
EMS. See Event Management Service (EMS).
EMS collector. An Event Management Service (EMS) process to which subsystems report
events.
emulate. To imitate the instruction set and address spaces of a different hardware system
by means of software. Emulator software is compatible with and runs software built for
the emulated system. For example, a TNS/R system emulates the behavior of a TNS
system when executing interpreted or accelerated TNS object code.
enclosure. A single sheet-metal structure and its enclosed set of system components. See
also base enclosure, stackable enclosure, system enclosure and peripheral enclosure.
enclosure interleaving. On HP NonStop™ S-series systems, configuring a mirrored disk
volume to use two separate system enclosures. For internal disk drives, the two disk
drives of the mirrored volume can be in separate enclosures. For external disk drives,
the adapters connected to the two disk drives of the mirrored volume can be in
separate enclosures.
endian. Denotes the significance of byte 0 in a multibyte structure such as a word. HP
NonStop™ servers are big-endian, where the most significant bit is contained in byte 0.
Intel® systems and HP AlphaServer OpenVMS and HP AlphaServer Tru64 UNIX
systems are little-endian, where the least significant bit is contained in byte 0.
Enterprise Storage System (ESS). A collection of magnetic disks, their controllers, and the
disk cache in a stand-alone cabinet or cabinets. These disks are configured by an
attached console and presented to the attached server as logical volumes that can be
a fraction of a physical volume or can span volumes.
environmental parameters. Subsystem Control Facility (SCF) session parameters set by
default or by using various SCF commands. The values associated with the
environmental parameters can be examined using the ENV command.