Specifications

Chapter 2 Hardware Installation and Configuration 2-3
expansion cabinet power sequencer. If the cabinet’s original factory configuration
has not been changed, then the cabinet should contain the correct power sequencer
connections.
Note – At the bottom of the expansion cabinet are two power sequencers. The front
power sequencer is hidden behind the front key switch panel. Remove the front key
switch panel to gain access to the power sequencer’s power cable.
2.1.3 Power Sequencer
For further information regarding power sequencer configuration, refer to Chapter 3
in the Sun StorEdge A3500/A3500FC Hardware Configuration Guide.
Caution – To prevent the possibility of data loss due to an inadvertent power
shutdown of an expansion cabinet, ensure that in a 3x15 configuration the power
sequencers are daisy chained front to front and back to back. The Local/Remote
switch should be set to Remote.
2.1.4 Local/Remote Switch
The Local/Remote switch on each power sequencer is factory set to Remote
(default). This allows power on/off control of each power sequencer through the
front key switch. If the Local/Remote switch is set to Local then the power on/off
control of each power sequencer is controlled by each power sequencer’s main
power circuit breaker switch.
2.1.5 SCSI and Fiber-Optic Cables
For further details regarding the SCSI and/or fiber-optic cables, refer to the Sun
StorEdge A3500/A3500FC Hardware Configuration Guide.
Each A3x00 is shipped from the factory with two 12-meter SCSI host cables. The
recommended maximum SCSI bus length is 25 meters. Exceeding this length can
cause SCSI or data errors. When calculating the maximum SCSI bus length in a
particular configuration, remember to include the internal SCSI bus of each device
which is 0.1 meters.
The example configuration in
FIGURE 2-1 shows a daisy chained multi-initiator
configuration consisting of two hosts connected to two A3x00 modules.