Sensu Check Disk

Table of Contents

• Overview
• Usage
  • check-disk-usage
  • metrics-disk-usage
• Configuration
  • Asset Registration
  • Check Definition
• Installation from Source
• Contributing

Overview

This plugin provides native disk instrumentation for monitoring and metrics collection in Sensu Go. It is a Golang replacement for sensu-plugins/sensu-plugins-disk-checks.

Features:

• Check disk usage with configurable warning and critical thresholds
• Collect detailed disk usage metrics (bytes, inodes, percentages)
• Filter by filesystem type and mount paths
• Cross-platform support (Linux, macOS, Windows)
• Native Go binary with no runtime dependencies

Usage

Checks

check-disk-usage

Check disk usage against warning and critical thresholds.

check-disk-usage --warning 80 --critical 90

Options:

  -w, --warning float           Warning threshold percentage for disk usage
  -c, --critical float          Critical threshold percentage for disk usage
  -i, --ignore-paths strings    Comma-separated list of mount paths to ignore
  -I, --include-paths strings   Comma-separated list of mount paths to include (if set, only these are checked)
  -x, --ignore-types strings    Comma-separated list of filesystem types to ignore
  -t, --include-types strings   Comma-separated list of filesystem types to include (if set, only these are checked)

Examples:

Check all filesystems with 80% warning and 90% critical thresholds:

check-disk-usage --warning 80 --critical 90

Check only ext4 filesystems:

check-disk-usage --warning 80 --critical 90 --include-types ext4

Ignore tmpfs and devtmpfs filesystems:

check-disk-usage --warning 80 --critical 90 --ignore-types tmpfs,devtmpfs

Check specific mount points:

check-disk-usage --warning 80 --critical 90 --include-paths /,/home

check-fstab-mounts

Verify that filesystems defined in /etc/fstab are actually mounted.

check-fstab-mounts

Options:

  -f, --fstab-path string       Path to fstab file (default "/etc/fstab")

Examples:

Check default fstab:

check-fstab-mounts

Check custom fstab file:

check-fstab-mounts --fstab-path /etc/fstab.backup

check-smart

Check SMART disk health status using smartctl.

check-smart --devices /dev/sda,/dev/sdb

Options:

  -d, --devices strings         Comma-separated list of devices to check (e.g., /dev/sda,/dev/sdb)
  -s, --smartctl-path string    Path to smartctl binary (default "smartctl")
  -c, --config-file string      Path to JSON config file with device list (default "/etc/sensu/conf.d/smart.json")

Examples:

Check specific devices:

check-smart --devices /dev/sda,/dev/sdb

Auto-detect devices:

check-smart

Use config file:

check-smart --config-file /etc/sensu/conf.d/smart.json

Note: Requires smartctl (from smartmontools package) and typically needs sudo permissions.

check-smart-status

Check SMART offline test status.

check-smart-status --devices /dev/sda

Options:

  -d, --devices strings         Comma-separated list of devices to check
  -s, --smartctl-path string    Path to smartctl binary (default "smartctl")
  -c, --config-file string      Path to JSON config file with device list (default "/etc/sensu/conf.d/smart.json")

Note: Requires smartctl and typically needs sudo permissions.

check-smart-tests

Check SMART self-test status and verify tests are running within expected intervals.

check-smart-tests --devices /dev/sda --short-test-interval 24 --long-test-interval 336

Options:

  -d, --devices strings              Comma-separated list of devices to check
  -s, --smartctl-path string         Path to smartctl binary (default "smartctl")
  -c, --config-file string           Path to JSON config file with device list (default "/etc/sensu/conf.d/smart.json")
  -l, --short-test-interval int      Maximum hours since last short test (default 24, 0 to disable)
  -t, --long-test-interval int       Maximum hours since last extended test (default 336, 0 to disable)

Examples:

Check with default intervals (24h for short, 14 days for long):

check-smart-tests --devices /dev/sda,/dev/sdb

Custom intervals:

check-smart-tests --devices /dev/sda --short-test-interval 12 --long-test-interval 168

Note: Requires smartctl and typically needs sudo permissions.

Metrics

metrics-disk-usage

Output disk usage metrics in Graphite plaintext format.

metrics-disk-usage

Options:

  -s, --scheme string           Metric naming scheme prefix (default "disk_usage")
  -i, --ignore-paths strings    Comma-separated list of mount paths to ignore
  -I, --include-paths strings   Comma-separated list of mount paths to include (if set, only these are checked)
  -x, --ignore-types strings    Comma-separated list of filesystem types to ignore
  -t, --include-types strings   Comma-separated list of filesystem types to include (if set, only these are checked)

Examples:

Output metrics for all filesystems:

metrics-disk-usage

Output metrics with custom scheme:

metrics-disk-usage --scheme servers.disk

Output metrics only for ext4 filesystems:

metrics-disk-usage --include-types ext4

Output format:

All metrics commands output in Graphite plaintext format with the following metrics per filesystem:

• used_bytes - Bytes used
• total_bytes - Total bytes
• free_bytes - Bytes free
• used_percent - Percentage used
• inodes_used - Inodes used
• inodes_total - Total inodes
• inodes_free - Inodes free
• inodes_used_percent - Percentage of inodes used

Configuration

Asset Registration

Assets are the best way to make use of this plugin. If you're not using an asset, please consider doing so!

---
type: Asset
api_version: core/v2
metadata:
  name: sensu-check-disk
spec:
  builds:
    - url: https://github.com/nmollerup/sensu-check-disk/releases/download/{{ version }}/sensu-check-disk_{{ version }}_linux_amd64.tar.gz
      sha512: REPLACE_WITH_SHA512
      filters:
        - entity.system.os == 'linux'
        - entity.system.arch == 'amd64'

Check Definition

Check disk usage:

---
type: CheckConfig
api_version: core/v2
metadata:
  name: check-disk-usage
spec:
  command: check-disk-usage --warning 80 --critical 90 --ignore-types tmpfs,devtmpfs
  runtime_assets:
    - sensu-check-disk
  subscriptions:
    - system
  interval: 60
  publish: true

Metrics collection:

---
type: CheckConfig
api_version: core/v2
metadata:
  name: metrics-disk-usage
spec:
  command: metrics-disk-usage --scheme disk_usage
  runtime_assets:
    - sensu-check-disk
  subscriptions:
    - system
  interval: 60
  output_metric_format: graphite_plaintext
  output_metric_handlers:
    - influxdb
  publish: true

Installation from Source

Download the latest version or create an executable from this source.

From source:

go install github.com/nmollerup/sensu-check-disk/cmd/check-disk-usage@latest
go install github.com/nmollerup/sensu-check-disk/cmd/metrics-disk-usage@latest

From release:

Download the latest release from the releases page.

Build from source:

git clone https://github.com/nmollerup/sensu-check-disk.git
cd sensu-check-disk
go build -o bin/check-disk-usage ./cmd/check-disk-usage
go build -o bin/metrics-disk-usage ./cmd/metrics-disk-usage

Contributing

Contributions are welcome! Please open an issue or submit a pull request.