If you already have proxmox metric collection enabled, just import dashboard.
Requires Proxmox VE >= 4.0!
Install graphite (i use go-carbon with carbonapi).
Carbon should listen on UDP port, 2003 by default.
For schema file, use something like
[carbon] pattern = ^carbon\. retentions = 60:90d [proxmox] pattern = ^proxmox\. retentions = 60:30d [default_1min_for_1day] pattern = .* retentions = 60s:1d
Next, go to /etc/pve/status.cfg on your proxmox cluster machine (create this file if it doesn't exist) with contents:
graphite: server your_carbon_server port 2003 path proxmox
Restart pvestatd (might not be needed). Metrics should start arriving to carbon.
Import dashboard and you're ready to go.