Spectra Logic T-Series Spectra T200 User Manual page 48

Chapter 2 — Architecture Overview
Up to 16 devices can be connected to a wide LVD SCSI bus. Keep in mind
that each drive increases the total length of the SCSI bus. Daisy chaining all
four drives in a DBA results in an internal bus length of approximately
20 feet (6 meters), which must be subtracted from the maximum allowed
length of 40 feet (12 meters) for an LVD SCSI bus. Also keep in mind that
connecting multiple devices on a single SCSI bus can impact the
performance of all devices on the bus. The data transmission rate to all
drives is limited to the maximum transfer rate of the SCSI bus.
Figure 19
buses. Notice that SCSI terminators installed on the bus expansion module
supply termination for each SCSI bus.
Internal SCSI bus
LVD SCSI cable
Wide SCSI connector (bus expansion module)
Internal SCSI connector (DBA to drive)
SCSI terminator
Figure 19 Daisy-chaining two direct-attach SCSI drives on two SCSI buses.
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User Guide
shows connecting the four drives in a DBA to two separate SCSI
Drive Bay Assembly
Drive 3
Drive 1
Drive 4
Drive 2
Bus expansion
module
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