Typically, the first Switch Fabric (SF) or CPM card installed in a redundant 7210 SAS-R6 and 7210 SAS-R12 chassis assumes the active CPM role, regardless of whether it is inserted in slot A or B. The next CPM installed in the same chassis then assumes the standby CPM role. If two CPMs are inserted simultaneously (or almost simultaneously) and boot at the same time, preference is given to the CPM installed in slot A.
If only one CPM is installed in a redundant 7210 SAS-R6 and 7210 SAS-R12, it becomes the active CPM regardless of the slot it is installed in.
To visually determine the active and standby designations, the Status LED on the faceplate is lit green (steady) to indicate the active designation. The Status LED on the second CPM faceplate is lit amber to indicate the standby designation.
The following output sample shows that the CPM installed in slot A is acting as the active CPM and the CPM installed in slot B is acting as the standby.
A:7210SASR1# show card
===============================================================================
Card Summary
===============================================================================
Slot Provisioned Type Admin Operational Comments
Equipped Type (if different) State State
-------------------------------------------------------------------------------
1 imm-sas-10sfp+1xfp up up
2 imm-sas-10sfp+1xfp up up
A cpm-sf-sas-R6 up up/active
B cpm-sf-sas-R6 up up/standby
===============================================================================
A:7210SASR1#
The following console message is displayed if a CPM boots, detects an active CPM, and assumes the role of the standby CPM.
...
Slot A contains the Active CPM
This CPM (slot B) is the standby CPM.