IBM DS8000 User Manual page 232

throughout the industry and that
therefore can be connected to other
systems complying with the same
standards. Applied to the DS8000, such
systems are those hosts that connect to
the DS8000 through SCSI or FCP
protocols. See also small computer system
interface and Fibre Channel Protocol.
organizationally unique identifier (OUI)
An IEEE-standards number that identifies
an organization with a 24-bit globally
unique assigned number referenced by
various standards. OUI is used in the
family of 802 LAN standards, such as
Ethernet and Token Ring.
original equipment manufacturer's information
(OEMI)
A reference to an IBM guideline for a
computer peripheral interface. The
interface uses ESA/390 logical protocols
over an I/O interface that configures
attached units in a multidrop bus
topology.
OS/390
The IBM operating system that includes
and integrates functions that many IBM
software products (including the MVS
operating system) previously provided for
the IBM S/390 family of enterprise
servers.
OUI See organizationally unique identifier.
P
panel The formatted display of information that
appears on a display screen.
parallel access volumes (PAV)
A licensed function of the DS8000 that
enables OS/390 and z/OS systems to
issue concurrent I/O requests against a
count key data logical volume by
associating multiple devices of a single
control-unit image with a single logical
device. Up to eight device addresses can
be assigned to a PAV. The PAV function
enables two or more concurrent write
operations to the same logical volume, as
long as the write operations are not to the
same extents. See also extent, I/O Priority
Queueing, and multiple allegiance.
parity A data checking scheme used in a
computer system to ensure the integrity
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of the data. The RAID implementation
uses parity to re-create data if a disk
drive fails.
path group
In System z architecture, a set of channel
paths that are defined to a control unit as
being associated with a single logical
partition (LPAR). The channel paths are in
a group state and are online to the host.
See also logical partition.
path group identifier
In System z architecture, the identifier
that uniquely identifies a given logical
partition (LPAR). The path group
identifier is used in communication
between the LPAR program and a device.
The identifier associates the path group
with one or more channel paths, thereby
defining these paths to the control unit as
being associated with the same LPAR. See
also logical partition.
PAV See parallel access volumes.
PCI See peripheral component interconnect.
PDU See protocol data unit.
PE See IBM product engineering.
peripheral component interconnect (PCI)
An architecture for a system bus and
associated protocols that supports
attachments of adapter cards to a system
backplane.
persistent FlashCopy
A state where a FlashCopy relationship
remains indefinitely until the user deletes
it. The relationship between the source
and target volumes is maintained after a
background copy completes.
physical path
A single path through the I/O
interconnection fabric that attaches two
units. For Copy Services, this is the path
from a host adapter on one DS8000
(through cabling and switches) to a host
adapter on anotherDS8000.
pinned data
Data that is held in cache until either an
error condition is corrected and it can be
moved to disk storage or until the data is
discarded by a host command. Pinned
data conditions can only occur on an ESS
Model 800 during fast-write or dual-copy
functions.