Data ONTAP7 and earlier
Does the order of the target ports listed in the output of igroup show -v indicate MPIO path selection?
The ordering of the target ports in the output of the command
igroup show -v reveals the order in which the host Host Bus Adapter (HBA) or initiator discovered the target ports and performed Port Login (PLOGI) and Process Login (PRLI).
The displayed order does not imply which target port is being used by the host's MPIO software as a primary or optimized path or as a secondary or non-optimized path.
ONTAP> igroup show -v my_solaris_igroup
OS Type: solaris
Member: 10:00:00:00:c9:XX:XX:ed (logged in on: 0b, vtic)
Member: 10:00:00:00:c9:XX:XX:fd (logged in on: vtic, 0c)
This output shows that two initiators are members of the initiator group
my_solaris_igroup . The first initiator,
10:00:00:00:c9:XX:XX:ed, is shown as being logged into target ports 0b and vtic.
The vtic port indicates that this initiator is logged in to the filer cluster partner node and that the cluster partner will forward FCP traffic to this filer node. In this example, the order in which the target ports appear, 0b and vtic, only indicates that the initiator discovered the 0b port first and the partner port, vtic, second.
The second initiator,1
0:00:00:00:c9:XX:XX:fd, discovered the ports in a different order. It has discovered the partner ports before the 0c port.
The order in which the target ports are discovered is of no consequence to how the target ports are utilized. The host's MPIO software will determine which paths are primary or optimized versus which paths are secondary or non-optimized.
In some cases, an initiator may continue to be shown as logged in when it is not. This occurs in situations where the initiator does not perform a Port Logout with the target port, such as being powered off or disconnected from the fibre channel fabric. This is a normal situation and does not cause any problems for the initiator when it performs a future Process Login.
Please see What do FCP Partner Path Misconfigured messages mean? for information on implications of path priorities.