vm setup

I'm running Proxmox VE on a PC with 4 physical cores. When I try to create an Ubuntu virtual machine using all 4 cores, it stops with errors during the setup process. I would appreciate if someone could advise me on how to resolve this issue.

Hi I am very new to proxmox and have the following setup: 2x 60gb ssd enterprise drives in zfs raid 1 where proxmox is installed that shows up as local and local-zfs - here I can create vm's without an issue, the problem of course being there is very little space. So I added 2x 900gb scsi 15k...