---
id: 8f344d36-6005-4bfa-aa98-4e68d571a174
type: fix
title: "Fix: health_check.py disk check excludes squashfs/tmpfs/devtmpfs to prevent snap mount false positives"
tags: [monitoring, claude-runner-monitoring, python, fix, homelab, snap]
importance: 0.7
confidence: 0.8
created: "2026-02-20T20:16:35.251352+00:00"
updated: "2026-02-20T20:16:35.251352+00:00"
---

## Problem

VM 106 (pihole1) runs Ubuntu with snap packages. Snap mounts are squashfs filesystems that are read-only and always report 100% disk usage. The `df` command in `health_check.py` was including these mounts, causing false critical alerts on any server with snap packages installed.

## Fix

Changed `df` command on line 228 of `health_check.py` from:

```bash
df -h --output=pcent,target
```

to:

```bash
df -h --output=pcent,target -x squashfs -x tmpfs -x devtmpfs
```

## Impact

Prevents false positive disk space alerts on any monitored server that has snap packages installed. Also excludes tmpfs and devtmpfs which are virtual/RAM filesystems that don't represent real disk usage concerns.

## Project

CT 302 claude-runner-monitoring, file: `health_check.py`