I’ve added 2 external USBs of 2TB each to my Proxmox server and created a Resource Pool called USB_HDD containing both. I created an Ubuntu VM, but I can’t allocate all 4TB to it in one go - it only allows me to add each one as a separate SCSI device. When I start to install the OS it only allows the install onto one of the 2TB devices. I though the point of pools was to make the actual disks transparent, and present the pool to the VM so it sees it as one lot of space. Am I doing something wrong, or do I have to have it as 2x2TB disks?
Only if you never want to use those disks for anything else on that server
In this case ‘adding disks’ could mean either direct pass-through, or just adding a virtual disk on each physical disk in Proxmox so they can be used for other things as well.