Clustering
Disk-to-Disk Backup
Downward
Compatible
FireWire
Hot
Swap Benefit
RAID
Overview
RAID
Comparison
Repeater
Benefits
SAN
Overview
Termination
Basics
Interface
& Connector
Reference
SCSI
Connectors
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Storage Dictionary
- tape drive
- The
machine, actually a collection of devices, that transports,
reads from and writes to a magnetic tape.
- target
- The
SCSI device, usually a peripheral, that performs an operation
requested by a SCSI initiator.
- terabyte
- 1,099,511,627,776
bytes, from the prefix "tera", which means trillion. Broadly,
one trillion bytes, or one thousand gigabytes.
- termination
- Electrical
connection at each end of the SCSI bus, composed of a set
of resistors, or possibly other components. Its function
is to provide a pull-up for open collector drivers on the
bus, and also an impedance match, to prevent signal reflections
at the ends of the cable. Depending on the internal circuitry,
a terminator can use simple resistors ("active terminator").
Terminators for single-ended and differential interfaces
are different and are not interchangeable. Browse to Termination
for more information.
- topology
- The
components used to connect two or more ports together. Also
a specific way of connecting those components, as in point-to-point
topology.
- transceiver
- A transmitter/receiver
module.
- transmission
character
- The
10-bit encoded form of a byte or special code using the
8B/10B encoding algorithm.
- transmission
word
- A set
of four transmission characters, 40 bits. A transmission
word is the smallest information unit transmitted in Fibre
Channel.
- TüV
- Technischer
Überwachungs Verein. Literally "Technical Watch-Over
Association". A German certifying body involved with product
safety for the European Community.
- twinax
- A cable
made from two parallel copper wires clad with insulation
and a shield, through which information is transmitted as
electrical pulses. Used for high-speed transmission over
short distances.
- twisted
pair
- Type
of cable consisting of two wires twisted together. It is
excellent and inexpensive for high-speed transmissions over
short distances.
- Ultra
SCSI
- Another
name for SCSI-3/FAST-20. See also FAST-SCSI.
- Ultra2
SCSI
- Also
called "Fast-40". An enhancement of SCSI that results in
doubling the Ultra SCSI data throughput speeds to 40 Megatransfers/sec
(40 MBytes/sec for 8-bit and 80 MBytes/sec for 16-bit).
The SCSI specification recognizes only LVD Ultra2 SCSI and
single-ended is not defined at this speed. Maximum allowable
Ultra2 cable length is 12 meters (39.4 feet).
- Ultra3
SCSI
- Also
called "Fast-80" or "Ultra160". Described in SPI-3, Ultra160
again doubles the data throughput speeds to 80 Megatransfers/sec
(160 MBytes/sec for 16-bit). Single-ended not defined at
this speed. Requires LVD signaling. SPI-3 also obsolete
HVD, SCAM and the 8-bit and 32-bit wide bus. U160/m is a
sub-set of Ultra160 SCSI that includes double transition
clocking, CRC and domain validation.
- VHDCI
- The
68-pin Very High Density Cable Interconnect (VHDCI) connector
introduced in the SPI-3 document of SCSI-3. The VHDCI connector
is a very small connector that allows placement of four
wide SCSI connectors on the back of a single PC card slot.
Physically, it looks like a miniature Centronics type connector.
It uses the regular 68-contact pin assignment.
- WAN
- Wide
Area Network.
-
WORM
- Write
Once Read Many. Optical storage device on which data is
permanently recorded. Data can be erased, but not altered,
and no additional data can be added.
- zwavelength
- A linear
value corresponding to a specific frequency.
- Zoning
- A method
of subdividing a storage area network into disjoint zones,
or subsets of nodes on the network. Storage area network
nodes outside a zone are invisible to nodes within the zone.
Moreover, with switched SANs, traffic within each zone may
be physically isolated from traffic outside the zone.
Publications
- Basics
of SCSI- fourth edition by Ancot Corporation (1998)
A general introduction to SCSI and an overview
Available directly from: Ancot Corporation
115 Constitution Drive
Menlo Park, California
Tel: (650) 322-5322
Fax: (650) 322-0455
Internet: www.ancot.com
- The
Book of SCSI by Peter M. Ridge (1995)
Co-authors: D.A. Deming, S. Groll, J. Heim, G.Islinger,
J.Lohmeyer
Publisher: No Starch Press, Daly City, California 94014
A general introduction to SCSI operation, its hardware,
installation in PCs, and troubleshooting.
Available at many bookstores.
- The
SCSI Encyclopedia, by Jeffrey D. Stai, published by ENDL
(1991)
A detailed description of basic and advanced operations
of SCSI-1 and SCSI-2.
Available at many bookstores, or directly from:
ENDL Publications,
14426 Black Walnut Court
Saratoga, California 95070
Tel: (408) 867-6630
- SCSI
Interconnection Guide Book,
by AMP Inc.
Catalog #65237. A good description of all types of SCSI
connectors, pinouts, cabling schemes, and cable adapters,
with many photos, illustrations and drawings.
Available directly from AMP Inc.,
Harrisburg, PA 17105.
Tel: (800) 522-6752
- What
is Fibre Channel?
by Ancot Corporation (1997)
Introduction and a brief overview of the protocol.
Available directly from:
Ancot Corporation
115 Constitution Drive
Menlo Park, California 94025
Tel: (650) 322-5322
Fax: (650) 322-0455
Internet: www.ancot.com
- Fibre
Channel-The Basics,
by G. Stephens & J. Dedek
Available directly from:
Ancot Corporation
115 Constitution Drive
Menlo Park, California 94025
Tel: (650) 322-5322
Fax: (650) 322-0455
Internet: www.ancot.com
- The
Computer Glossary
by Alan Freedman
Anacom
135 West 50th Street
New York, NY 10020
- SNIA
Storage Networking Industry Association
2570 West El Camino Real Suite 304
Mountain View, CA 94040-1313 USA
Phone: (650) 949-6750
Fax: (650)949-6755
Email: info@snia.org
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