boot – Install Debian buster without booting from USB/CD

I currently have Debian 9 and OpenMediaVault4 installed on my WD Cloud Home and I’m trying to find a way to install Debian buster so I can upgrade to OMV5.

The only reason I managed to install the current system is because I found a .img that automated the whole installationprocess, but I can’t find anything similar for Buster/OMV5.

At the moment I have Buster netinstall img burned to a USB, which is plugged in to the WD Cloud Home. I can access the USB just fine with Putty, and all files and directories are there but I don’t know how to get the installation started.

If I try reboot the system with the USB I lose the connection with putty and can’t reconnect again. And since the installation require human input I sort of need to have access to the system through putty or something similar, so that I can use keyboard and my screen.

So is there any way at all I can start the installation from just having access to the installation.img on the usb?