SCF Reference Manual for the Storage Subsystem (G06.27+, H06.04+)

Glossary
SCF Reference Manual for the Storage Subsystem—529937-008
Glossary-7
I/O multifunction (IOMF) 2 CRU
I/O multifunction (IOMF) 2 CRU. A HP NonStop S-series customer-replaceable unit (CRU)
that connects an I/O enclosure to a processor enclosure through a ServerNet cable
and supplies power to the components within the IOMF 2 CRU as well as redundantly
to the disk drives, SCSI terminators, and ServerNet adapters in that enclosure. The
IOMF 2 CRU contains a power supply, a service processor (SP), a ServerNet router 2,
an Ethernet controller, three configurable ServerNet ports, and three SCSI ServerNet
addressable controllers (S-SACs) in a single unit. IOMF 2 CRUs are supported on
G06.10 and later software RVUs.
IOP. See input/output process (IOP).
KB. See kilobyte (KB).
Kernel subsystem. In G-series RVUs, the subsystem for configuration and management of
the Subsystem Control Facility (SCF) subsystem managers that are generic
processes, some system attributes, and the ServerNet X and Y fabrics.
kilobyte (KB). A unit of measurement equal to 1024 bytes. See also gigabyte (GB),
megabyte (MB), and terabyte (TB).
load. (1) To transfer the HP NonStop operating system image or a program from disk into a
computer’s memory so that the operating system or program can run. (2) To insert a
tape into a tape drive, which prepares it for a tape operation (read or write).
LDEV. Logical device. The HP term for a disk in the ESS.
logical unit number (LUN). The logical unit in the ESS that maps the LDEV onto a port.
Specification of the port and LUN specifies an LDEV.
M8xxx disk. A model M8xxx Fibre Channel disk drive that resides in slots 1 through 14 of
a Fibre Channel disk module (FCDM) connected to FCSAs in an IOAM enclosure.
MB. See megabyte (MB).
Measure product. A HP utility used to gauge system performance.
media changer. See robot.
megabyte (MB). A unit of measurement equal to 1,048,576 bytes (1024 kilobytes). See also
gigabyte (GB), kilobyte (KB), and terabyte (TB).
microcode. Any machine code or data that can run in a microprocessor. HP produces two
types of microcode for HP NonStop S-series systems: volatile and nonvolatile. Volatile
microcode is loaded into the volatile random-access memory (RAM) of some types of
printed wiring assemblies (PWAs) and is not retained in a host PWA when power to the
PWA is interrupted.
mirrored volume. A pair of identical disk drives that are used together as a single logical
volume. One drive is considered primary and the other is called the mirror. Each byte