Dot Hill Systems SANnet II 200, Installation, Operation And Service Manual

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Appendix B Cabling JBODs B-7
Caution –
Physical drive IDs are set based on the cabling on the array when it is
powered up. If you are switching from single-bus mode to split-bus mode or from
split-bus mode to single-bus mode, the physical drive IDs change after you power off,
change the cabling, and then power on. If you change physical drive IDs on the array,
ensure that your application points to the correct IDs.
B.6 Cabling a Split-Bus, Multi-Initiator JBOD
Configuration
There are two important features to note with the split-bus, multi-initiator JBOD
configuration:
■
The lower input ports on the JBOD must be terminated with an HBA host
connection or external terminator. The upper I/O SCSI connectors are auto-
terminated.
■
In a split-bus configuration, the physical drive ID numbers automatically change
according to the cabling.
Multi-initiator mode has more than one host connection on a SCSI channel.
Figure B-4 shows a multi-initiator, split-bus configuration where each host is
connected to each host channel. This configuration is common for failover protection
in a network cluster environment.
When you remove one or more host cables for maintenance purposes, insert an
external terminator into each empty port to maintain the physical drive IDs for the
active host connections.
Note –
The I/O module is hot-serviceable, which means that you can replace it or
change its cables while the array is powered on, but the SCSI host buses connected to
the array must be inactive.