I like Munin for small environments. Dead easy to set up and a very concise UI. I've written plugins .. I love it. Where I get frustrated is scalability of RRD

I like Munin for small environments. Dead easy to set up and a very concise UI. I've written plugins .. I love it. Where I get frustrated is scalability of RRDTool. Every data set has its own file so you get into this IO nightmare. I solved this for a while by storing them in a RAM disk. Ultimately I set up InfluxDB+Grafana. It is a lot more work and last I tried, InfluxDB does not support downsampling of older data, so instead of two years of history we have 90 days. The collector from one version to the next renamed most of the datapoints so the Grafana dashboards broke ... (Oh and of course also Munin looks like the 90s, which doesn't bother me, but sometimes gives decision makers cause to believe my solution is not hip.)