HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Maintenance and Service Guide (EK-G80MS-SA. C01, March 2005)

Glossary
273HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software
Maintenance and Service Guide
reduced
A term that indicates that a mirrorset or RAIDset is missing one member because the member
failed or was physically removed.
redundancy
The provision of multiple interchangeable components to perform a single function in order to
cope with failures and errors. A RAIDset is considered to be redundant when user data is
recorded directly to one member and all of the other members include associated parity
information.
regeneration
(1) The process of calculating missing data from redundant data. (2) The process of recreating a
portion of the data from a failing or failed disk drive using the data and parity information from
the other members within the storageset.
The regeneration of an entire RAIDset member is called reconstruction. See also reconstruction.
SCSI
Small Computer System Interface. (1) An American National Standards Institute (ANSI)
interface standard defining the physical and electrical parameters of a parallel I/O bus used to
connect initiators to devices. (2) A processor-independent standard protocol for system-level
interfacing between a computer and intelligent devices including hard drives, floppy disks,
CD-ROMs, printers, scanners, and others.
replacement policy
The policy specified by a switch with the SET FAILEDSET command indicating whether a
failed disk from a mirrorset or RAIDset is to be automatically replaced with a disk from the
spareset. The two switch choices are AUTOSPARE and NOAUTOSPARE.
SCSI device
(1) A host computer adapter, a peripheral controller, or an intelligent peripheral that can be
attached to the SCSI bus. (2) Any physical unit that can communicate on a SCSI bus.
SCSI device ID number
A bit-significant representation of the SCSI address referring to one of the signal lines,
numbered 0 through 7 for an 8-bit bus, or 0 through 15 for a 16-bit bus. See also target ID
number.
SCSI ID number
The representation of the SCSI address that refers to one of the signal lines numbered 0
through 15.
SCSI port
(1) Software: The channel controlling communications to and from a specific SCSI bus in the
system. (2) Hardware: The name of the logical socket at the back of the system unit to which a
SCSI device is connected.