Move bootable iso from CD/DVD Drive to Hard Disk

[leechy00]

I've got my Proxmox VM setup with a CD/DVD drive, USB Device and (small) Hard Disk.
It's set to boot from the USB drive, which holds a bootable ISO disk.
How can I transfer the OS from the USB drive to the Hard Disk? (or even the CD drive).

These are instructions in a non-virtual environment, ...but I can't 'see' the hard disk when I use fdisk in the Console for the server.
https://hiveon.com/knowledge-base/guides/hdd_move/

(I'm super new and learning as I go, pls keep it simple and many thanks!)

 

[LnxBil]

The guide describes one way to do this. Maybe just backup your VMs, reinstall on you harddisk and restore the backup if you're not that into near-hardware stuff.