Yup, you are doing it wrong and need more understanding.
We'll try again, as you are obviously not reading and or understanding all the doc's and links we point you to.
You'll need two scsi adapters, each with their own disks to make this work, and at the moment you have one scsi adapter with all the disks.
Each vios will need its own scsi adapter and disks to install to but you don't have that without being able to power up the expansion drawers.
You install vio, but it has all the disks and the only scsi adapter.
When you try to install the second vio there is nothing left because the first vio has all the disks.
When you shut down the first VIO then the other can see the scsi adapter and disks but they really belong to the first one.
You need the expansion drawers so that each VIO can have its own scsi adapter and its own disks to install to.
Read.......no point in keep playing if you don't understand the basics.
HTH