Node exporter can not read system statistics
Each time I curl <ip of router>:9100 I receive the following log error:
level=error ts=2021-03-02T03:55:34.739Z caller=collector.go:161 msg="collector failed" name=zfs duration_seconds=0.000164491 err="couldn't get sysctl: no such file or directory"
Updated by Daniel Kimsey 3 months ago
The issue is that in node_collector v1.0.0 added ZFS support by default by querying sysctl for the various stats. It tests for support in Linux but doesn't seem to do so on BSD. Hence the errors.
I'm of the opinion this is an incorrect behavior on the node_exporter's part. Maybe pfSense could make a change in the pkg defaults to disable the zfs collector. In the meantime, there's an easy fix. Simply add `--no-collector.zfs` to the Extra Flags parameter under Service > Prometheus node_exporter. This will disable the gathering of these metrics and stop the error spam.
edit: Looking around, it's probably somewhat odd it's a FreeBSD box without ZFS enabled :)