IBM Partner Pavilion DS4100 manual 138

small computer system interface (SCSI). A standard
hardware interface that enables a variety of peripheral
devices to communicate with one another.
small form-factor pluggable (SFP). An optical
transceiver that is used to convert signals between
optical fiber cables and switches. An SFP is smaller
than a gigabit interface converter (GBIC). See also
gigabit interface converter.
SNMP. See Simple Network Management Protocol and
SNMPv1.
SNMP time-out. The maximum amount of time the
SANavigator tool will wait for a device to respond to a
request. The specified time applies to one retry only.
SNMP trap event. (1) (2) An event notification sent by
the SNMP agent that identifies conditions, such as
thresholds, that exceed a predetermined value. See
also Simple Network Management Protocol.
SNMPv1. The original standard for SNMP is now
referred to as SNMPv1, as opposed to SNMPv2, a
revision of SNMP. See also Simple Network
Management Protocol.
SRAM. See static random access memory.
SSA. See serial storage architecture.
static random access memory (SRAM). Random
access memory based on the logic circuit know as
flip-flop. It is called static because it retains a value as
long as power is supplied, unlike dynamic random
access memory (DRAM), which must be regularly
refreshed. It is however, still volatile, meaning that it can
lose its contents when the power is turned off.
storage area network (SAN). A dedicated storage
network tailored to a specific environment, combining
servers, storage products, networking products,
software, and services. See also fabric.
Storage Array Identifier (SAI or SA Identifier). The
Storage Array Identifier is the identification value used
by the DS4000 Storage Manager host software
(SMClient) to uniquely identify each managed storage
server. The DS4000 Storage Manager SMClient
program maintains Storage Array Identifier records of
previously-discovered storage servers in the host
resident file, which allows it to retain discovery
information in a persistent fashion.
storage management station. A system that is used
to manage the storage subsystem. A storage
management station does not need to be attached to
the storage subsystem through the fibre-channel
input/output (I/O) path.
storage partition. Storage subsystem logical drives
that are visible to a host computer or are shared among
host computers that are part of a host group.
storage partition topology. In the DS4000 Storage
Manager client, the Topology view of the Mappings
window displays the default host group, the defined host
group, the host computer, and host-port nodes. The
host port, host computer, and host group topological
elements must be defined to grant access to host
computers and host groups using logical drive-to-LUN
mappings.
subnet. An interconnected but independent segment
of a network that is identified by its Internet Protocol (IP)
address.
sweep method. A method 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. A fibre-channel device that provides full
bandwidth per port and high-speed routing of data by
using link-level addressing.
switch group. A switch and the collection of devices
connected to it that are not in other groups. Switch
groups are discovered by the SANavigator tool and
displayed with a gray background on the Physical and
Data Path maps.
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. See Transmission Control Protocol.
TCP/IP. See Transmission Control Protocol/Internet
Protocol.
terminate and stay resident program (TSR
program). A program that installs part of itself as an
extension of DOS when it is executed.
topology. The physical 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. A device that is used to transmit and
receive data. Transceiver is an abbreviation of
transmitter-receiver.
translated loop port (TL_port). A port 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).
138 IBM TotalStorage DS4100 Storage Server: Installation, User’s, and Maintenance Guide