[1.10.2] error parsing file: Too few fields in mount string

[pasztorl]

Hi,

node_filesystem_avail_bytes not reported, and I couldn't find this message in the source code so I'm stuck looking for the error. I've attached the logs. Could someone please take a look?

prometheus-prometheus-node-exporter-n4jns.log

[lakshmiyagnanandareddy]

Hi @pasztorl,

This is a configuration issue caused by a race condition reading /proc/self/mountinfo.

Fix

Add run to your mount exclusions:

--collector.filesystem.mount-points-exclude=^/(dev|proc|sys|run|var/lib/kubelet/.+)($|/)

If using Helm:

helm upgrade prometheus-node-exporter prometheus-community/prometheus-node-exporter \
  -n monitoring \
  --set 'extraArgs[0]=--collector.filesystem.mount-points-exclude=^/(dev|proc|sys|run|var/lib/kubelet/.+)($|/)' \
  --reuse-values

Verify (after ~2 min for pod restart)

# Should return 0
kubectl logs -n monitoring <pod-name> --tail=100 | grep "collector failed" | wc -l

# Should show filesystem metrics
kubectl exec -n monitoring <pod-name> -- wget -q -O- localhost:9100/metrics | grep node_filesystem_avail_bytes

---

If this doesn't resolve it, please share:

1. How you deployed Node Exporter (Helm chart or kubectl manifest)
2. The exact configuration you applied
3. Current error messages from pod logs

Let me know how it goes!

[Yzzzi]

Hi @lakshmiyagnanandareddy

Looks like I am facing exactly the same issue as OP.
Tried to apply fix you proposed but it didn't work, collector is still failing.

1. Deployed via official helm chart, version 4.49.1, into k3s cluster version v1.28.6+k3s2
2. config.yaml
3. The errors are slightly different on different nodes, although, alike
   From one node:

time=2026-02-06T19:50:13.579Z level=ERROR source=collector.go:168 msg="collector failed" name=filesystem duration_seconds=0.108221905 err="error parsing file: Too few fields in mount string: 77765 26 0:8250 / /run/k3s/containerd/io.containerd.runtime.v2.task/"

From the other one:

time=2026-02-06T19:52:41.006Z level=ERROR source=collector.go:168 msg="collector failed" name=filesystem duration_seconds=0.275330447 err="error parsing file: Too few fields in mount string: 2652 28 0:2852 / /var/lib/kubelet/pods/50e73ded-71b7-45e9-8b04-8bf3def"

Also tried to play around with regex, also tried different flags, like --collector.filesystem.mount-points-exclude, --collector.filesystem.ignored-mount-points, but it didn't help either.

Let me know if I can provide any additional information that may be helpful!