Compaq Infortrend Manual De Usuario
Infortrend
10-10
Table 10 - 1 ID Mapping Status (Normal Operation)
Channel
ID
Status
Target Chip
0 (Primary ID)
Active
Pri. Controller
channel 0
0
1 (Secondary ID)
Standby
Sec. Controller
channel 0
1 (Secondary ID)
Active
Sec. Controller
channel 1
1
0 (Primary ID)
Standby
Pri. Controller
channel 1
In the event of controller failure (say, the Primary controller fails), the
once inactive ID (chip) will become active:
once inactive ID (chip) will become active:
Table 10 - 2 ID Mapping Status (Controller Failed)
Channel
ID
Status
Target Chip
0 (Primary ID)
Active
Pri. Controller
channel 0 – Failed!
0
1 (Secondary ID)
Standby- becomes
Active!
Sec. Controller
channel 0
1 (Secondary ID)
Active
Sec. Controller
channel 1
1
0 (Primary ID)
Standby
Pri. Controller
channel 1- Failed!
Figure 10 - 8 Controller Failover
For every channel that is actively serving I/Os, there is another on the
alternate controller that stays idle and will inherit the task should its
counterpart fail.
alternate controller that stays idle and will inherit the task should its
counterpart fail.
An exception to this is that active IDs may co-exist on single or
multiple host channels. As long as I/O bandwidth is not of the
concern, then standby chips may not be necessary.
multiple host channels. As long as I/O bandwidth is not of the
concern, then standby chips may not be necessary.