IBM Partner Pavilion T400 Switch User Manual


 
the drive. Log sense data is used to diagnose problems,
especially if the problems are intermittent.
SCSI wrap plug. A connector mechanism that
connects to a SCSI port for the purpose of testing the
Ultrium 2 Tape Drives circuitry for the SCSI interface.
SCSI wrap test. A diagnostic that can be run on the
Ultrium 2 Tape Drive to determine whether the circuitry
functions properly to and from the SCSI connector.
second. One sixtieth of a minute.
selection time-out. Following the selection of an
option (for example, a data transfer), the period of time
during which it is determined that there is a bad
connection between the server and the drive.
sense data. Data that describes an I/O error. Sense
data is presented to a server in response to a Sense
I/O command.
serial interface. An interface that sequentially or
consecutively executes two or more operations in a
single device, such as an arithmetic and logic operation.
server. A functional unit that provides services to one
or more clients over a network. Examples include a file
server, a print server, or a mail server. The IBM
Eserver pSeries, IBM Eserver iSeries, HP, and Sun
are servers. Synonymous with host.
ship group. The group of supplies, cords, or
documentation that is shipped with the Ultrium 2 Tape
Drive.
shipping environment. The temperature, relative
humidity rate, and wet bulb temperature of the
environment to which the Ultrium 2 Tape Drive is
exposed when it is transferred from one location to
another.
short-wave cable. In Fibre Channel technology, a
laser cable that uses a wavelength of 780 nanometers
and is only compatible with multimode fiber.
single-character display. Located at the front of the
Ultrium 2 Tape Drive, an LED that presents an
alphabetical or numeric code which represents a
diagnostic or maintenance function, error condition, or
informational message.
sleep mode. A power-management function that
causes the Ultrium 2 Tape Drives electronics to
automatically enter a low-power mode by which to
conserve energy.
Small Computer Systems Interface (SCSI). A
standard used by computer manufacturers for attaching
peripheral devices (such as tape drives, hard disks,
CD-ROM players, printers, and scanners) to computers
(servers). Pronounced scuzzy. Variations of the SCSI
interface provide for faster data transmission rates than
standard serial and parallel ports (up to 160 megabytes
per second). The variations include:
v Fast/Wide SCSI: Uses a 16-bit bus, and supports
data rates of up to 20 MBps.
v SCSI-1: Uses an 8-bit bus, and supports data rates
of 4 MBps.
v SCSI-2: Same as SCSI-1, but uses a 50-pin
connector instead of a 25-pin connector, and
supports multiple devices.
v Ultra SCSI: Uses an 8- or 16-bit bus, and supports
data rates of 20 or 40 MBps.
v Ultra2 SCSI: Uses an 8- or 16-bit bus and supports
data rates of 40 or 80 MBps.
v Ultra3 SCSI: Uses a 16-bit bus and supports data
rates of 80 or 160 MBps.
v Ultra160 SCSI: Uses a 16-bit bus and supports data
rates of 160 MBps.
soft addressing. Pertaining to the Fibre Channel drive
(Model T400F), a method that enables the drive to
dynamically arbitrate its AL_PA with other Fibre Channel
devices on the loop. The AL_PA enables the drive to
communicate with other devices.
software. Programs, procedures, rules, and any
associated documentation pertaining to the operation of
a computer system.
speed matching. A technique used by the Ultrium 2
Tape Drive to dynamically adjust its native
(uncompressed) data rate to the slower data rate of a
server. Speed matching improves system performance
and reduces backhitch.
status light. Located at the front of the Ultrium 2 Tape
Drive, an LED that can be green or amber, and (when
lit) solid or flashing. The condition of the light represents
the state of the drive.
Storage Area Network (SAN). A high-speed
subnetwork of shared storage devices. A SANs
architecture makes all storage devices available to all
servers on a LAN or WAN. As more storage devices are
added to a SAN, they too will be accessible from any
server in the larger network. Because stored data does
not reside directly on any of a networks servers, server
power is used for business applications, and network
capacity is released to the end user.
storage environment. The temperature, relative
humidity rate, and wet bulb temperature of the
environment in which the Ultrium 2 Tape Drive is
nonoperational and is being kept for future use.
subscription channel connector (SC). A push-pull
type of optical connector that features high density, low
loss, low backreflection, and low cost.
switch. A network infrastructure component to which
multiple nodes attach. Unlike hubs, switches typically
have the ability to switch node connections from one to
Glossary 113