HP 3PAR StoreServ Concepts Guide: HP 3PAR OS 3.1.3

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.
PCM Power Cooling Module. A hardware component that includes the battery, fan, and power supply.
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
primary and secondary paths are not user configurable and are determined by drive magazine
placement.
promote For physical copies: to break the association between a physical copy and a base volume by
changing the physical copy into an independent base volume. For virtual copies: to copy the
changes from a virtual copy back onto the base volume, therefore overwriting the base volume
with the virtual copy.
rack The EIA-standard rack within a cabinet that holds the components of a system.
rack filler panel A panel used to seal off an empty 1U, 2U, or 4U space on the rack. All empty spaces in the rack
must be sealed for EMI and airflow considerations.
rack unit (U) The standard unit of height for an EIA-standard rack or components housed in an EIA-standard
rack: equivalent to 1.75 in. (4.45 cm).
RAID Redundant array of independent disks.
RAID 0 set Striped rows of chunklets on two or more physical disks. A RAID 0 set offers no data redundancy.
RAID 10 (RAID 1)
set
A group of mirrored chunklets.
RAID 50 (RAID 5)
set
A group of parity-protected chunklets. Also known as a parity set.
RAID MP RAID Multi-Parity. A group of double-parity chunklets.
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