Specifications

Glossary GL–17
remote copy A feature intended for disaster tolerance and replication of data from one
storage subsystem or physical site to another subsystem or site. It also
provides methods of performing a backup at either the local or remote site.
With remote copy, user applications continue to run while data movement
goes on in the background. Data warehousing, continuous computing, and
enterprise applications all require remote copy capabilities.
remote copy set A bound set of two units, one located locally and one located remotely for
long distance mirroring. The units can be a single disk, or a storageset,
mirrorset, or RAIDset. A unit on the local controller is designated as the
“initiator” and a corresponding unit on the remoted controller is designated as
the “target.”
See also association set.
request rate The rate at which requests are arriving at a servicing entity.
RFI Radio frequency interference. The disturbance of a signal by an unwanted
radio signal or frequency.
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.
SBB STORAGEWORKS building block. (1) A modular carrier plus the interface
required to mount the carrier into a standard STORAGEWORKS shelf. (2)
any device conforming to shelf mechanical and electrical standards installed
in a 3.5-inch or 5.25-inch carrier, whether it is a storage device or power
supply.
SCSI Small computer system interface. (1) An 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.
SCSI-A cable A 50-conductor (25 twisted-pair) cable generally used for single-ended,
SCSI-bus connections.