HP XP20000/XP24000 Manual page 72

mirroring The consistency (usability) of data in a volume (for example, S-VOL).
consistency
MR Magnetoresistive.
mutual hot Two servers that are poised to cover for each other if necessary.
standby system
NAS Network attached storage.
node An environment where instances can be executed, logically speaking. Physically,
a processor, which is an element of a cluster system.
NVS Nonvolatile storage.
OFC Open Fibre Control.
OLM Optical link module.
OS Operating system.
PA Physical address.
parity group A set of hard disk drives that have the same capacity and that are treated as
one group. A parity group contains both user data and parity information, which
enables user data to be accessed if one or more drives in the group is not
available.
partition The act of dividing a specific physical disk into two or more areas as if there are
two or more physical disks.
path A path is created by associating a port, a target, and a LUN ID with one or more
LDEVs. Also known as a LUN.
PCA Printed circuit assembly.
PCB Printed circuit board.
PCI Peripheral component interconnect. The PCI bus typically runs at speeds of 33
MHz or 66 MHz and is usually 32 bits wide. This means that it passes 32 bits
of data simultaneously as if down 32 separate wires. Some of the most recent
computers include wider 64-bit PCI buses, and already certain very high-end
video capture cards offer improved performance if connected to a 64-bit PCI
bus.
PDU Power distribution unit. The rack device that distributes conditioned AC or DC
power within a rack.
port A physical connection that allows data to pass between a host and the disk
array. The number of ports on an HP XP disk array depends on the number of
supported I/O slots and the number of ports available per I/O adapter. The HP
XP family of disk arrays supports Fibre Channel (FC) ports as well as other port
types. Ports are named by port group and port letter, such as CL1-A. CL1 is the
group, and A is the port letter.
P-P Point-to-point.
R-SIM Remote service information message.
72 Glossary