xhimera, Thanks for your solution.
I was also playing with 3 proxmox servers, and did mass up with the cluster.
I did follow xhimera with another solution as well.
I did this on the 3 servers:
pve-manager/4.3-14/3a8c61c7 (running kernel: 4.4.35-1-pve)
# stop service
systemctl stop...