storage area network
A network that connects a company’s
heterogeneous storage resources.
storage capacity
The amount of data that a storage
medium can hold; usually expressed in
kilobytes, megabytes, or gigabytes.
storage complex
A configuration of one or more storage
units that is managed by a management
console.
storage device
A physical unit that provides a mechanism
to store data on a given medium such that
it can be subsequently retrieved. See also
disk drive module.
storage extent
The minimum contiguous range of storage
on a physical storage device, array, or
rank that can be allocated to a local
volume
storage image
A partitioning of a storage unit that
provides emulation of a storage server
with one or most storage devices that
provides storage capability to a host
computer. You can configure more than
one storage image on a storage unit.
storage server
A physical unit that manages attached
storage devices and provides an interface
between them and a host computer by
providing the function of one or more
logical subsystems. The storage server
can provide functions that the storage
device does not provide. The storage
server has one or more clusters.
storage unit
A physical unit that consists of a storage
server that is integrated with one or more
storage devices that provide storage
capability to a host computer.
storage unit identifier
A unique identifier for a storage unit that
consists of a manufacturer, a model
number, a type number, a plant of
manufacture, and a sequence number.
striping
A technique that distributes data in bit,
byte, multibyte, record, or block
increments across multiple disk drives.
subagent
An extension to an SNMP agent that
permits a user to dynamically add, or in
some cases replace, additional
management variables in the local MIB,
thereby providing a means of extending
the range of information that network
managers can access. See also agent.
subchannel
A logical function of a channel subsystem
associated with the management of a
single device.
subordinate storage unit
The physical unit that receives commands
from the master storage unit and is
specified when a Global Mirror session is
started. The subordinate storage unit
forms consistency groups and performs
other Global Mirror processing. A
subordinate storage unit can be controlled
by only one master storage unit. Contrast
with master storage unit.
subsystem identifier (SSID)
A number that uniquely identifies a logical
subsystem within a computer installation.
support catcher
See catcher.support catcher telephone number
The telephone number that connects the
support catcher server to the DS8000 to
receive a trace or dump package. See
also support catcher and remote technical
assistance information network.
switched fabric
A fibre-channel topology in which ports are
interconnected through a switch. Fabric
switches can also be interconnected to
support numerous ports on a single
network. See also arbitrated loop and
point-to-point connection.
symmetrical multiprocessor (SMP)
An implementation of a multiprocessor
computer consisting of several identical
processors configured in a way that any
subset of the set of processors is capable
of continuing the operation of the
computer. TheDS8000 contains four
processors set up in SMP mode.
synchronous write
A write operation whose completion is
indicated after the data has been stored
on a storage device.

Glossary 349