How to create SEA in Sharing Mode ?

Detailed Explanation 

Shared Ethernet Adapter in sharing mode is creating bridge between Physical Adapter and Two Virtual Ethernet Adapter. For example physical adapter supports 24 as native and 25, 26 and 27 as additional Port VLAN ID (PVID).

For SEA in Sharing mode plan is to create two Virtual Ethernet Adapter one having 24 as IEEE 802.1q compatible. Another Virtual Ethernet Adapter having 25, 26, 27 as IEEE 802.1q configured.

Shutdown the VIOS1 and Create First Virtual Ethernet adapter given below HMC console (entY1)

Second Virtual Ethernet Adapter (entY2)

Then Power on the VIOS with the changed profile. Login to VIOS and execute below command

mkvdev -sea entX -default entY1 -defaultid 24 -vadapter entY1,entY2 -ha_mode=sharing -migrate -auto

Follow the same procedure for another VIOS2 also starting from Step 1. Power off the VIOS2 and add First Virtual Ethernet adapter (entY1)

Configure the Second Ethernet Adapter of VIOS2 (entY2)

Power on the VIOS2 and login to the vios and execute the command to create the SEA in sharing mode

mkvdev -sea entX -default entY1 -defaultid 24 -vadapter entY1,entY2 -ha_mode=sharing -migrate -auto

After SEA creation was successful list the SEA entZ as 

# lsdev | grep Shared
entZ       Available             Shared Ethernet Adapter
# lsattr -El entZ | grep -i sharing
ha_mode         sharing   High Availability Mode                                                             True

SEA create successfully using ha_mode as Sharing.