Checkmk monitors infrastructure: servers, network gear, virtual machines, containers, databases, and applications. It grew out of the Nagios world but replaced most of Nagios’s configuration pain with automatic discovery: install an agent or point it at an SNMP device, and it finds what to monitor and sets sensible thresholds.

Features

• Agent-based monitoring for Linux, Windows, and more, plus agentless checks via SNMP, APIs, and special agents for platforms like VMware and cloud providers
• Service discovery: new file systems, interfaces, and services are found automatically
• Hundreds of official and community check plugins
• Built-in graphing, dashboards, and alerting with notification rules
• Designed to scale to large environments with low resource use

Editions

Edition	License	Notes
Community (formerly Raw)	GPL-2.0	Free and open source; the self-hosted core
Pro	Commercial	Distributed monitoring, advanced dashboards, reporting
Ultimate	Commercial	Kubernetes and cloud-native, OpenTelemetry
Cloud	SaaS	Managed

The Community edition is fully capable for homelabs and small businesses.

Deployment

Checkmk is distributed as DEB and RPM packages for Debian, Ubuntu, RHEL, and SUSE, and as a Docker image. After installing, you create a monitoring “site” with omd create, which is an isolated instance with its own web interface and user. Download packages from the Checkmk website rather than building from source.

Checkmk vs the alternatives

• Zabbix: similar enterprise scope, fully open source across all features, more manual configuration
• LibreNMS: focused on network devices via SNMP
• Prometheus and Grafana: metrics-first and cloud-native, excellent for applications, more assembly required
• Netdata and Beszel: lightweight per-host monitoring with little setup

Our Prometheus, Grafana, and Netdata guide compares the metrics-first approach.

License

Community edition: GPL-2.0. Other editions are commercial.

Links

• Repository
• Website