I never used Proxmox, so after having read great comments about it tried to install it on a couple small mini PCs I had around just to test some functionalities

I never used Proxmox, so after having read great comments about it tried to install it on a couple small mini PCs I had around just to test some functionalities, but every time it failed. If memory serves (was like 1-2 months ago) on both machines the installer complained it couldn't find the partition to install. Both machines would install and run other Linux distros flawlessly. No idea how to solve that problem.