node_exporter collector failure for zfs err="couldn't get sysctl: no such file or directory"

Host operating system: output of uname -a

FreeBSD stable/14-n265566 aarch64 1400500 1400500

node_exporter version: output of node_exporter --version

% node_exporter --version
node_exporter, version (branch: , revision: unknown)
build user:
build date:
go version: go1.20.8
platform: freebsd/arm64
tags: unknown

node_exporter command line flags

(defaults)

node_exporter log output

Nov 15 17:14:22 REDACTED node_exporter[58452]: ts=2023-11-15T17:14:22.737Z caller=collector.go:169 level=error msg="collector failed" name=zfs duration_seconds=0.000465773 err="couldn't get sysctl: no such file or directory"

(every 15 seconds in /var/log/daemon.log)

Workaround for now is editing /usr/local/etc/rc.d/node_exporter and finding this line:

: ${node_exporter_args:=""

and editing it like so:

: ${node_exporter_args:="--no-collector.zfs"}
then restarting node_collector.

Start by reproducing the zfs collector failure on FreeBSD stable/14 with the default node_exporter flags, then inspect the zfs collector's sysctl lookup. The issue mentions /usr/local/etc/rc.d/node_exporter only as a workaround; determine the intended handling for the missing sysctl and verify that the recurring collector error is resolved.