I connected my TrueNAS box to Graphite and Grafana. I had both of these running in a Talos Kubernetes cluster. The metrics were sent over correctly, but the imported dashboard I was using from the Grafana community showed no data because it expected older TrueNAS metric paths. So, I got this fixed after remapping the panels. Then, I found another issue. It interpreted an ARC value in bytes as megabytes and displayed 12.7 PB instead of roughly 12 GB!
Check out my full post detailing what I ran into, why I saw what I did and then how I fixed them. At the end, I was able to have a really good TrueNAS monitoring dashboard in Grafana.