Taking a massive stab in the dark, but looks like if you removed the physical hba assigned to the lpar from the lpar and then your path for hdisk0 went missing:
Your disks are not coming from the VIO. Without going into an in depth look at your system, are you sure you are presenting disks up from the VIO? Are you sure your lpar has virtual adapters presented up from the VIO? I mean, the whole point of running a VIO is so that takes all (or most) of your adapters so you can present them to the lpars as part of the virtualization layer. There should be very few instances where you need physical adapters assigned the a lpar running under a VIO.
Also from ioinfo from the openfirmware, its common to see that message. openfirmware is not aware so to speak to anything not apart of the system.
IF I manage to find time, I will show you how one of my environments are setup. Currently a lot of cruft on my plate that I must address first. Also, you should note that I'm not using NPIV, and my setup may not be the 'IBM recommended' way.
In the meantime, here's some handy links:
Access Denied
And since you are using npiv:
AIX for System Administrators
02-18-2020
