Add import existing disk image into Proxmox

proxmox-import-disk-image.txt

#
# The official PVE docs on how to prepare cloud-init templates:
#   https://pve.proxmox.com/wiki/Cloud-Init_Support#_preparing_cloud_init_templates
#
# Additional guides and resources:
#   https://dae.me/blog/2340/how-to-add-an-existing-virtual-disk-to-proxmox/
#   https://pve.proxmox.com/pve-docs/qm.1.html

# use the Qemu/KVM Virtual Machine Manager to import the disk
qm importdisk 107 Univention-App-kopano-core-KVM.qcow2 local-lvm

# rescan all storages and update disk sizes and unused disk images
qm rescan

# edit the vm config
# /etc/pve/qemu-server/107.conf 
bootdisk: scsi1
scsi0: local-lvm:vm-107-disk-0,size=32G
scsi1: local-lvm:vm-107-disk-1,size=50G  <--- new image 

# you can use the Proxmox VE Storage Manager
# to list all newly scanned disks
pvesm list local-lvm

# show your vm
qm list