elements must be defined to grant access to host
computers and host groups using logical drive-to-LUN
mappings.
striping. Splitting data to be written into equal blocks
and writing blocks simultaneously to separate disk
drives. Striping maximizes performance to the disks.
Reading the data back is also scheduled in parallel, with
a block being read concurrently from each disk then
reassembled at the host.
subnet. An interconnected but independent segment
of a network that is identified by its Internet Protocol (IP)
address.
sweep method. Amethod of sending Simple Network
Management Protocol (SNMP) requests for information
to all the devices on a subnet by sending the request to
every device in the network.
switch. Afibre-channel device that provides full
bandwidth per port and high-speed routing of data by
using link-level addressing.
switch group. Aswitch and the collection of devices
connected to it that are not in other groups.
switch zoning. See zoning.
synchronous write mode. In remote mirroring, an
option that requires the primary controller to wait for the
acknowledgment of a write operation from the
secondary controller before returning a write I/O request
completion to the host. See also asynchronous write
mode,remote mirroring,Metro Mirroring.
system name. Device name assigned by the vendor’s
third-party software.
TCP. SeeTransmission Control Protocol.
TCP/IP. SeeTransmission Control Protocol/Internet
Protocol.
terminate and stay resident program (TSR
program). Aprogram that installs part of itself as an
extension of DOS when it is executed.
topology. Thephysical or logical arrangement of
devices on a network. The three fibre-channel
topologies are fabric, arbitrated loop, and point-to-point.
The default topology for the disk array is arbitrated loop.
TL_port. See translated loop port.
transceiver. Adevice that is used to transmit and
receive data. Transceiveris an abbreviation of
transmitter-receiver.
translated loop port (TL_port). Aport that connects
to a private loop and allows connectivity between the
private loop devices and off loop devices (devices not
connected to that particular TL_port).
TransmissionControl Protocol (TCP). A
communication protocol used in the Internet and in any
network that follows the Internet Engineering TaskForce
(IETF) standards for internetwork protocol. TCP
provides a reliable host-to-host protocol between hosts
in packed-switched communication networks and in
interconnected systems of such networks. It uses the
Internet Protocol (IP) as the underlying protocol.
TransmissionControl Protocol/Internet Protocol
(TCP/IP). Aset of communication protocols that
provide peer-to-peer connectivity functions for both local
and wide-area networks.
trap. In the Simple Network Management Protocol
(SNMP), a message sent by a managed node (agent
function) to a management station to report an
exception condition.
trap recipient. Receiver of a forwarded Simple
Network Management Protocol (SNMP) trap.
Specifically,a trap receiver is defined by an Internet
Protocol (IP) address and port to which traps are sent.
Presumably,the actual recipient is a software
application running at the IP address and listening to
the port.
TSR program. See terminate and stay resident
program.
uninterruptible power supply. Asource of power
from a battery that is installed between a computer
system and its power source. The uninterruptible power
supply keeps the system running if a commercial power
failure occurs, until an orderly shutdown of the system
can be performed.
user action events. Actions that the user takes, such
as changes in the storage area network (SAN), changed
settings, and so on.
worldwide port name (WWPN). Aunique identifier for
a switch on local and global networks.
worldwide name (WWN). Aglobally unique 64-bit
identifier assigned to each Fibre Channel port.
WORM. See write-once read-many.
write-once read many (WORM). Any type of storage
medium to which data can be written only a single time,
but can be read from any number of times.After the
data is recorded, it cannot be altered.
WWN. See worldwide name.
zoning. (1) In Fibre Channel environments, the
grouping of multiple ports to form a virtual, private,
storage network. Ports that are members of a zone can
communicate with each other,but are isolated from
ports in other zones. (2)A function that allows
segmentation of nodes by address, name, or physical
port and is provided by fabric switches or hubs.
Glossary 211