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ATTO Technology FibreBridge 3300D Installation and Operation Manual
4 Connecting SCSI devices to SCSI ports
ATTO FibreBridge SCSI ports are used to connect SCSI storage devices into the Fibre Channel Storage
Area Network (SAN).
Each SCSI port is totally independent from the
any other SCSI port. This means that each bus is
capable of supporting 15 devices and each bus is
capable of 80 or 160 MB/sec. (Ultra, Ultra2 or
Ultra160).
However, you may use externally provided
software striping to create a RAID 0 group that
includes devices from both SCSI busses to
increase overall performance.
Another advantage of independent SCSI ports is
that each SCSI bus auto-negotiates the
appropriate sync rates with the connected devices.
If slower devices are mixed with faster Ultra160
devices, the bus will communicate at the rate of
the slowest device, thus wasting the performance
capabilities of the faster devices. You should
connect slower devices to one SCSI port and
connect faster devices on the other port on your
FibreBridge.
The FibreBridge supports a wide variety of SCSI
storage devices including stand-alone drives,
removable drives, JBODs, RAIDs, tape, CD and
DVD drives, changers, and libraries, magneto
optical drives.
To connect SCSI devices to the ATTO
FibreBridge:
1
C
onnect a VHDCI connector from the SCSI
device to a port on the FibreBridge 3300.
2
Check the type of cable, cable length limit
and number of devices recommended for
each port. It is important to keep cable
lengths as short as possible to ensure the
highest signal quality and
performance.These cable lengths include
the wiring inside the devices.
3
Set the IDs of the SCSI devices connected to
the bridge to a value other than 7. It is
recommended to use a sequential ID
starting at 0 for each device. Each SCSI port
in the ATTO FibreBridge has an internal
factory setting ID of 7, typical for a SCSI
initiator device.
NOTE The entire SCSI bus will operate at the speed of the
slowest device. If you wish to mix devices of different SCSI
speeds on the bridge, it is best to place them on separate
busses. That is, put the slower devices on bridge SCSI bus 0,
and the faster devices on bridge SCSI bus 1. Each bus is
independent so each can operate at different speeds.
4
Terminate each SCSI bus after the last
device. The bridge is terminated internally.
Device type
Cable limit
Ultra SCSI Single Ended (SE)
1.5 meters
Ultra SCSI High Voltage Differential (HVD)
25 meters
Ultra2 SCSI Low Voltage Differential (LVD)
12 meters
Summary of Contents for FibreBridge 3300R
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