Nagios Core vs Observium
A side-by-side comparison of two self-hosted monitoring & status options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Nagios Core | Observium |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Health score | 84 · Excellent | 0 · At risk |
| Category | Monitoring & Status | Monitoring & Status |
| License | GPL-2.0 | GPL-3.0 |
| Language | C | Shell |
| Setup difficulty | Hard | Medium |
| Min. RAM | 512 MB | 1,024 MB |
| Deployment | bare-metal, docker, source | bare-metal, source |
| GitHub stars | ★ 2,045 | ★ 1 |
| First released | 1999 | 2010 |
| Replaces | SolarWinds, PRTG | SolarWinds, PRTG |
What are Nagios Core and Observium?
Nagios Core
Nagios Core is the open-source monitoring engine that watches hosts, services, and network devices, alerting when problems occur. It is highly extensible through plugins and remains a long-standing standard in IT monitoring.
- Host and service checks
- Massive plugin ecosystem
- Flexible notification rules
- Proven at scale
Observium
Observium is a network monitoring platform that auto-discovers devices via SNMP and collects performance and health data. It focuses on a clean interface and low-maintenance operation for network infrastructure.
- SNMP auto-discovery
- Network device dashboards
- Low maintenance design
- Historical performance graphs
Nagios Core vs Observium: key differences
Nagios Core is written in C, while Observium is built with Shell. Licensing differs — GPL-2.0 for Nagios Core versus GPL-3.0 for Observium. Nagios Core is the lighter option, starting around 512 MB of RAM against 1,024 MB for Observium. Nagios Core is the more established project (first released 1999), while Observium arrived in 2010. Nagios Core has the considerably larger community, at 2,045 GitHub stars versus 1. Nagios Core lists first-class Docker deployment; Observium does not.
Why pick each one
Choose Nagios Core if…
- Battle-tested and stable
- Enormous plugin library
Watch out for
- Configuration is text-file heavy
- Dated web interface
Choose Observium if…
- Discovers devices automatically
- Clean interface
Watch out for
- Community edition lags the paid version
- SNMP-centric
Frequently asked questions
Is Nagios Core or Observium better?
Neither is universally better. Nagios Core has the larger community, while Observium is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are Nagios Core and Observium free and open-source?
Yes. Nagios Core is licensed under GPL-2.0 and Observium under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Nagios Core and Observium with Docker?
Nagios Core: yes. Observium: check the project docs for container support.
Which is lighter on resources, Nagios Core or Observium?
Nagios Core has the smaller minimum footprint at 512 MB of RAM, compared to about 1,024 MB for Observium. Real-world usage depends on library size, user count, and enabled features.