I needed a lightweight VM on proxmox (needed to be a VM, not a KVM for extra security) and I used to be familiar with arch. It was a VM to experiment with so I didn't want to take the time of a full set up and working through the partitioning in the Arch Wiki so I just went to https://archlinux.org/download/ and downloaded a VM.
Proxmox actually lets you import qcow2 files so I just transferred it via ssh and ran
qm importdisk 112 arch.qcow2 local-lvm
qm rescan https://mangolassi.it/topic/21751/import-a-qcow2-into-proxmox
deleted the default hard disk I had attached and then adjusted the boot order!