Specifications

GL–14 Compaq StorageWorks HSG80 Array Controller ACS Version 8.5 Maintenance and Service Guide
parity A method of checking if binary numbers or characters are correct by counting
the ONE bits. In odd parity, the total number of ONE bits must be odd; in even
parity, the total number of ONE bits must be even. Parity information can be
used to correct corrupted data. RAIDsets use parity to improve the availability
of data.
parity bit A binary digit added to a group of bits that checks to see if there are errors in
the transmission.
parity RAID See RAIDset.
partition A logical division of a container, represented to the host as a logical unit.
peripheral device Any unit, distinct from the CPU and physical memory, that can provide the
system with input or accept any output from it. Terminals, printers, tape
drives, and disks are peripheral devices.
point-to-point
connection
A network configuration in which a connection is established between two,
and only two, terminal installations. The connection may include switching
facilities.
port (1) In general terms, a logical channel in a communications system. (2) The
hardware and software used to connect a host controller to a communications
bus, such as a SCSI bus or serial bus.
Regarding the controller, the port is (1) the logical route for data in and out of
a controller that can contain one or more channels, all of which contain the
same type of data. (2) The hardware and software that connects a controller to
a SCSI device.
port_name A 64-bit unique identifier assigned to each Fibre Channel port. The
Port_Name is communicated during the logon and port discovery process.
preferred address The AL_PA which an NL_Port attempts to acquire first during initialization.
primary cabinet The primary cabinet is the subsystem enclosure that contains the controllers,
cache modules, external cache batteries, and the PVA module.
private NL_Port An NL_Port which does not attempt login with the fabric and only
communicates with NL_Ports on the same loop.
public NL_Port An NL_Port that attempts login with the fabric and can observe the rules of
either public or private loop behavior. A public NL_Port may communicate
with both private and public NL_Ports.