HP 4000.6000.8000 Enterprise Virtual Arrays User Manual
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data entry mode
The state in which controller information can be displayed or controller
configuration data can be entered. On the Enterprise Storage System, the
controller mode is active when the LCD on the HSV Controller OCP is Flashing.
default disk group The first disk group created at the time the system in initialized. The default
disk group can contain the entire set of physical disks in the array or just a
few of the disks.
See also
.
Detailed Fault
View
An HSV Controller OCP display that permits a user to view detailed information
about a controller fault.
device channel
A channel used to connect storage devices to a host I/O bus adapter or
intelligent controller.
device ports
Controller pair device ports connected to the storage system’s physical disk drive
array through the Fibre Channel drive enclosure. Also called a device-side port.
device-side ports
See
.
DIMM
Dual Inline Memory Module. A small circuit board holding memory chips.
dirty data
The write-back cached data that has not been written to storage media even
though the host operation processing the data has completed.
disk drive
A carrier-mounted storage device supporting random access to fixed size blocks
of data.
disk drive blank
A carrier that replaces a disk drive to control airflow within a drive enclosure
whenever there is less than a full complement of storage devices.
drive enclosure
A unit that holds storage system devices such as disk drives, power supplies,
blowers, I/O modules, transceivers, or EMUs.
drive enclosure
event
A significant operational occurrence involving a hardware or software
component in the drive enclosure. The drive enclosure EMU reports these events
to the controller for processing.
disk failure pro-
tection
A method by which a controller pair reserves drive capacity to take over the
functionality of a failed or failing physical disk. For each disk group, the
controllers reserve space in the physical disk pool equivalent to the selected
number of physical disk drives.
disk group
A physical disk drive set or pool in which a virtual disk is created. A disk group
may contain all the physical disk drives in a controller pair array or a subset
of the array.
disk migration
state
A physical disk drive operating state. A physical disk drive can be in a stable
or migration state:
•
Stable—The state in which the physical disk drive has no failure nor is a
failure predicted.
•
Migration—The state in which the disk drive is failing, or failure is predicted
to be imminent. Data is then moved off the disk onto other disk drives in
the same disk group.
disk replacement
delay
The time that elapses between a drive failure and when the controller starts
searching for spare disk space. Drive replacement seldom starts immediately in
case the “failure” was a glitch or temporary condition.
drive blank
See
drive enclosure
See
.
dual-loop
A configuration where each drive is connected to a pair of controllers through
two loops. These two Fibre Channel loops constitute a loop pair.
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Glossary