Resizing Private Storage Max Size Template

Trying to resize the Private Storage Max Size using the GUI but its greyed out. Is there a way to do this with qvm?

Based on my experience system storage resize option can be unavailable, but never seen that happening with private storage. Have you run out of disk space by any chance?
Anyway, I think you are looking for this.

I have a qube that for some reason won’t boot after increasing the private storage max size using
the gui. Then tried to resize to smaller disk using lvresize and still will not boot

I just destroyed a template by increasing system size from 20GB to 40GB. And I cannot revert back to 20GB. The Qubes / AppVMs based on that template won’t boot.

In Dom0 Terminal, I ran:

qvm-volume resize template:private 20000000

And I got this response:

For your own safety, shrinking of private is disabled. If you really know what you are doing, resize filesystem manually first, then use -f option.

How can I fix this? I don’t know how to proceed.

Did you do this using GUI in template Settings window?
Can you open this template terminal or it’s not booting?

I increased system sized from 20 to 40 using GUI in template Qube Settings window. I was able to open the template terminal. The template is booting. BUT THE QUBEs based on this template are not booting.

Did you shutdown/restart your template after increasing system size before you try to start qubes based on it?

Thanks. After starting then shutting down the template, the Qubes work again. Thank you!

But how can I decrease the system size? I would still like to do so.