HP 3PAR InForm OS 3.1.1 Concepts Guide

During loop initialization, the nodes present on the arbitrated loop identify themselves and acquire
addresses on the loop. No data can be transferred on an arbitrated loop until initialization
completes.
logging Temporarily saving data to logging logical disks when physical disks are out of service (due to
failure or during replacement procedures).
logging LD Logging logical disk. A logical disk used for logging. During system setup, the system creates a
20 GB RAID 10 logging LD for each controller node in the system.
LUN Logical Unit Number. A number used to access a virtual volume that has been assigned to a
particular host on a particular port.
maintenance PC A laptop computer running Windows 2000 used by a field technician to initiate direct
communication with the system service processor and controller nodes.
matched-set VLUN
template
A rule that allows a particular host connected to a particular port to see a virtual volume as a
specified LUN.
message code A keycode that identifies a system alert.
mirror One member of a group of mirrored chunklets, which is also known as a RAID 1 set.
mirroring A data redundancy technique used by some RAID levels and in particular RAID 1 to provide data
protection on a storage array.
navigation tree The navigation tree appears in a pane that occupies the left side of the HP3PAR Management
Console main window. Each system and system object appears as an icon in the navigation tree.
no stale snapshots Virtual copy policy that prevents changes being written to a base volume when it does not have
enough snapshot data or administration space to prevent virtual copies from becoming invalid,
or stale, as a result.
node cabinet A cabinet that houses the system backplane and controller nodes.
original parent
base volume
The original base volume from which a series of virtual or physical copies has been created. Any
volume can be the parent from which one or more virtual copies is created, but for each set of
related copies there is only one original parent base volume.
parent volume A virtual volume from which a virtual or physical copy is made.
parity A data redundancy technique used by some RAID levels (in particular RAID 5) to provide data
protection on a storage array.
parity set position The group of chunklets that occupy the same position within a RAID 5 logical disk parity set.
PCI load card An electronic circuit board that is inserted into a controller node’s PCI slot. The PCI load card
allows the node to recognize an unoccupied PCI slot.
PDU Power Distribution Unit. A device that takes in AC power from a main power source (for example,
an electrical wall outlet) and distributes the power to the power supplies in a system.
physical copy A point-in-time copy of an entire virtual volume.
physical disk A dual-ported Fibre Channel disk mounted onto a drive magazine.
physical parent The source volume for a physical copy.
physical size The total actual raw storage allocated to a logical disk, as determined by its size and RAID type.
port-presents
VLUN template
A VLUN template that allows any host connected to a particular port to see a virtual volume as
a specified LUN.
power bank A group of four connected AC outlets within the power distribution unit (PDU). There are two
power banks in each PDU.
power supply A device that converts current from an AC line into appropriate DC levels and provides that
power to a system component.
preserved data Data that is suspended in the system’s cache memory due to backend failure.
preserved data
logical disks
RAID 10 logical disks created by the system during initial system setup to store preserved data.
The logical capacity of the preserved data logical disks is equal to the sum of all data cache
memory of the system.
primary path Connection between a controller node initiator port and a physical disk that is used by default.
When the primary path cannot be used (a failure condition), the secondary path is used. The
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