RS-1600-X24 User Guide
226
SCSI port
A SCSI port is an opening at the back of a router that provides connection between the SCSI
adapter and SCSI bus.
Serial Transmission
The transfer of data characters one bit at a time, sequentially, using a single
electrical path. See
Parallel Transmissio
n.
Simple Network Management Protocol (SNMP)
SNMP is the Internet standard protocol, defined in
STD 15, RFC 1157, developed to manage nodes on an Internet Protocol (IP) network.
small computer system interface (SCSI)
SCSI is an industry standard for connecting peripheral
devices and their controllers to an initiator. Storage devices are daisy-chained together and connected to
a host adapter. The host adapter provides a shared bus that attached peripherals use to pass data to and
from the host system. Examples of devices attached to the adapter include disk drives, CD-ROM discs,
optical disks, and tape drives. In theory, any SCSI device can be plugged into any SCSI controller.
small form-factor pluggable (SFP)
Type of connector.
speed
Speed shows the speed of the FC port interface.
Storage Area Network (SAN)
SAN refers to the network behind servers that links one or more servers
to one or more storage systems. Each storage system could be RAID, tape backup, tape library, CD-
ROM library, or JBOD. SANs operate with both SCSI and networking (IP) protocols. Servers and
workstations use the FC network for shared access to the same storage device or system. Legacy SCSI
systems are interfaced using an FC-to-SCSI bridge.
Storage Manager module
The controller module which includes an FC-AL 2Gb/s
LRC I/O module
with
integral Xyratex X24 RAID controller.
target
A target is a device (peripheral) that responds to an operation requested by an initiator (host
system). Although peripherals are generally targets, a peripheral may be required to act temporarily as
an initiator for some commands (for example, SCSI EXTENDED COPY command).
terminator block/termination
A terminator block (or termination) refers to the electrical connection at
each end of a SCSI bus. The terminator block is composed of a set of resistors, or possibly other
components. The function of a terminator block is to provide a pull-up for open collector drivers on the
bus, and also impedance matching to prevent signal reflections at the ends of the cable. SCSI buses
require that a terminator be placed on the 68-pin high-density SCSI connector on the last SCSI
peripheral. Data errors may occur in a SCSI bus that is not terminated.
topology
A network topology refers to the physical layout of nodes on a network. Topologies range from
local network topologies to WAN topologies. FC topologies include point-to-point, FC-AL, and fabric.
trap
In the context of SNMP, a trap is an unsolicited message sent by an agent to a management
station. The purpose is to notify the management station of some unusual event.
unkill
In Active-Active mode, when a surviving controller removes the reset from the other controller, it
unkills it. The other controller will reboot and attempt to come online.
write-back cache
Memory on the controller that stores data changes until they are written to the disk
drives. In most applications, using the controller’s write-back cache improves performance and ensures
data integrity. Disk drives also have write-back cache, which should be disabled for most applications.
Summary of Contents for RS-1600-X24
Page 1: ...RS 1600 X24 User Guide Part No 43061 01A Issue 1 0 June 23 2003 ...
Page 9: ...Contents ix Index 229 ...
Page 10: ...x RS 1600 X24 User Guide ...
Page 50: ...RS 1600 X24 User Guide 32 ...
Page 56: ...RS 1600 X24 User Guide 38 ...
Page 70: ...RS 1600 X24 User Guide 52 ...
Page 112: ...RS 1600 X24 User Guide 94 ...
Page 170: ...RS 1600 X24 User Guide 152 ...
Page 190: ...RS 1600 X24 User Guide 172 ...
Page 206: ...RS 1600 X24 User Guide 188 ...
Page 230: ...RS 1600 X24 User Guide 212 ...
Page 238: ...RS 1600 X24 User Guide 220 ...
Page 246: ...RS 1600 X24 User Guide 228 ...