HP XP P9500 Storage - Manual (Page 406)

Out-of-Band
Method This method is transferring a command from the client or the server to the virtual command device
in the SVP via LAN, assigning a RAID Manager operation instruction to the DKC, and executing
it.
P-VOL Primary volume.
PA Physical address.
parity group A set of hard disk drives that have the same capacity and that are treated as one group. A parity
group contains both user data and parity information, which enables user data to be accessed
if one or more drives in the group is not available.
path A path is created by associating a port, a target, and a LUN ID with one or more LDEVs. Also
known as a LUN.
PAV Parallel access volume.
PCB Printed circuit board.
PDEV Physical device.
PDP Power distribution panels.
PDU Power distribution unit. The rack device that distributes conditioned AC or DC power within a
rack.
port A physical connection that allows data to pass between a host and the disk array. The number
of ports on a disk array depends on the number of supported I/O slots and the number of ports
available per I/O adapter. The P9000 and XP family of disk arrays supports Fibre Channel (FC)
ports and other port types. Ports are named by port group and port letter, such as CL1-A. CL1 is
the group; A is the port letter.
PSUE Pair suspended-error.
PSUS Pair suspended-split.
R-VOL Remote volume.
RAID group A group of disks configured to provide enhanced redundancy, performance, or both. Specifically,
four or eight physical hard disk drives (HDDs) installed in a P9000 or XP disk array and assigned
a common RAID level. In an XP disk array this is also referred to as an array group or parity
group.
RAID level A configuration of disk drives that uses striping, mirroring, and parity to improve performance
and data availability and reliability.
RAID Manager The CLI configuration and replication tool for the P9000 or XP disk array that system administrators
can use to enter RAID Manager commands from open-system hosts to perform Continuous Access,
Business Copy, Database Validator, and Data Retention operations, as well as provisioning
commands on logical devices.
RAID1-level data
storage A RAID that consists of at least two drives that use mirroring (100 percent duplication of the
storage of data). There is no striping. Read performance is improved since either disk can be
read at the same time. Write performance is the same as for single disk storage.
RAID1/5 Specific RAID architectures.
RAID5-level data
storage A RAID that provides data striping at the byte level and also stripe error correction information.
RAID5 configurations can tolerate one drive failure. Even with a failed drive, the data in a RAID5
volume can still be accessed normally.
RAID6-level data
storage A RAID that provides data striping at the byte level and also stripe error correction information.
RAID6 configurations can tolerate two drive failures. Even with two failed drives, the data in a
RAID6 volume can still be accessed normally. RAID6 read performance is similar to RAID5, since
all drives can service read operations, but the write performance is lower than that of RAID5
because the parity data must be updated on multiple drives.
RCU Remote control unit.
RDC Remote dual copy. Also known as remote copy.
remote instance The instance with which the local instance communicates, as configured in the HORCM_INST
section of the RAID Manager instance configuration file.
406 Glossary