HP 4000.6000.8000 Enterprise Virtual Arrays - Manual (Page 170)

M
management
agent The HP P6000 Command View software that controls and monitors the Enterprise storage system.
The software can exist on more than one management server in a fabric. Each installation is a
management agent.
management
agent event Significant occurrence to or within the management agent software, or an initialized storage cell
controlled or monitored by the management agent.
mean time
between failures See MTBF.
metadata Information that a controller pair writes on the disk array. This information is used to control and
monitor the array and is not readable by the host.
micro meter See µm.
mirrored caching A process in which half of each controller’s write cache mirrors the companion controller’s write
cache. The total memory available for cached write data is reduced by half, but the level of
protection is greater.
mirroring The act of creating an exact copy or image of data.
MTBF Mean Time Between Failures. The average time from start of use to first failure in a large population
of identical systems, components, or devices.
multi-mode fiber A fiber optic cable with a diameter large enough (50 microns or more) to allow multiple streams
of light to travel different paths from the transmitter to the receiver. This transmission mode enables
bidirectional transmissions.
N
Network Storage
Controller See NSC.
node port A device port that can operate on the arbitrated loop topology.
non-OFC (Open
Fibre Control) A laser transceiver whose lower-intensity output does not require special open Fibre Channel
mechanisms for eye protection. The Enterprise storage system transceivers are non-OFC compatible.
NONCRITICAL
Condition A drive enclosure EMU condition report that occurs when one or more elements inside the enclosure
have failed or are operating outside of their specifications. The failure does not affect continued
normal operation of the enclosure. All devices in the enclosure continue to operate according to
their specifications. The ability of the devices to operate correctly may be reduced if additional
failures occur. UNRECOVERABLE and CRITICAL errors have precedence over this condition. This
condition has precedence over INFORMATION condition. Early correction can prevent the loss
of data.
NSC Network Storage Controller. The HSV Controllers used by the Enterprise storage system.
NVRAM Nonvolatile Random Access Memory. Memory whose contents are not lost when a system is
turned Off or if there is a power failure. This is achieved through the use of UPS batteries or
implementation technology such as flash memory. NVRAM is commonly used to store important
configuration parameters.
O
occupancy alarm
level A percentage of the total disk group capacity in blocks. When the number of blocks in the disk
group that contain user data reaches this level, an event code is generated. The alarm level is
specified by the user.
OCP Operator Control Panel. The element that displays the controller’s status using indicators and an
LCD. Information selection and data entry is controlled by the OCP push-button.
online/nearonline An online drive is a normal, high-performance drive, while a near-online drive is a
lower-performance drive.
operator control
panel See OCP.
170 Glossary