Infortrend RAID Controller Manual

12-8
interface and multiple IDs are created to facilitate active-active
operation. Each controller occupies either a Primary ID or a
Secondary ID on drive channels. One logical unit is assigned to the
Primary controller and the other the Secondary controller. In the
event when one controller fails, the existing controller will inherit IDs
from the failed unit and continue I/Os.
Figure 12 - 9 Traffic Distribution
Logical Drive 0 Logical Drive 1
Host LUN Mapping ID0 / LUN* ID1 / LUN*
Logical Drive Assignment Primary Secondary
Drive Channel 2 3
When configuring a logical unit, users should assign the logical unit
to the Primary or the Secondary controller. Once the assignment is
done, logical unit(s) assigned to the Primary controller can only be
mapped to the Primary ID on host channel; Logical unit(s) assigned to
the Secondary controller can only be mapped to the Secondary ID on
host channel.
The channel ID (Primary/Secondary) assignment for a SCSI controller
may look like this:
Primary Controller
ID
Secondary Controller ID
Host Chl SCSI ID PID = 0 SID = 1
Drive Chl SCSI ID 7 (or 8 for the dual 6 suggested (or 9 for the
redundant chassis) dual redundant chassis)
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