How to get Storage Metrics Across All Site Collections for Private Teams Channels

[luvsql]

We use quite a lot of private channels, not only because of permissions between channels and Teams, but when you have a large number of files and use OneDrive, separating files into separate Private Channels enables us to have separate doc libraries and not worry about limitations with the OneDrive Sync.  Also, each channel gets 1Tb limit etc etc it works great for us.

However, none of these show up in the SP Admin Centre active size.  There is a tremendous amount of data being used from our tenant level storage, yet have no way to reconcile to see who is using what.

If we get to a point of having to purchase more expensive storage, we have to see what channels are using what so costs can be allocated.  Also, we just have to see this as we've found some users are keeping backup Revit models that are supposed to be in the AutoDesk cloud and not SP (there are so many reasons).

1. Since each Private Teams Channel is a separate Site Collection, why isn't it listed in the Admin Centre?  It IS the same tenant.

This is our main site collection:  https://companyname.sharepoint.com/ 

This is a Private Teams Channel:  https://companyname.sharepoint.com/sites/TeamsChannelName

They are the same main site collection so it's very puzzling.

2. If it can't be listed in the admin centre, are there reports we can run to tabulate ALL the site collections together?   I don't know why they made these such a mystery to admins.  

[#2]

There is an update coming to the SPO Admin Center that will display PC there with all this info. While this happens, what you can do is get the information through PowerShell

[#3]

Me and PowerShell do not have the best relationship unfortunately. Even Microsoft support yesterday couldn't get connected to our tenant via PS after 45 minutes for some other issue.

[#4]

It must be magic because LITERALLY just now I now see "Channel Sites" and a link in the Admin Centre to which it now shows all of the Private Channels and their individual sizes. I still have to open them all one at a time, however, it's better than nothing.