System monitoring tools are essential in server management. However, especially on low-resource VDS or dedicated servers, how much RAM these tools themselves consume can become an annoying issue. Glances and Netdata are two of the most popular monitoring tools. So which one consumes less RAM? Let's compare with concrete numbers.
A Brief Look at Glances and Netdata
Glances is a terminal-based monitoring tool written in Python. Although it also offers a web interface, its real strength lies in the command line. Netdata, on the other hand, is written from scratch in C, offering visually rich web panels, and is a very comprehensive system. Both collect basic metrics like CPU, RAM, disk, and network. But their architectures and resource usage are very different.
RAM Consumption Comparison
Glances RAM Usage
Glances, in its default installation, consumes about 20-35 MB of RAM. I tested this: on an Ubuntu 22.04 server, with only the Glances service running, the free -m output showed 29 MB. If you enable some plugins (Docker, RAID, etc.), it can go up to 50 MB. But still quite modest.
Netdata RAM Usage
Netdata, on the same server, requires on average 80-120 MB of RAM. This number is high due to more plugins and an internal database (similar to Prometheus). If specific plugins like MySQL or Nginx are active, it can even reach 200 MB. For example, a Netdata installation with all plugins enabled consumed 145 MB in my tests.
When Should You Choose Which?
If your server only has 512 MB of RAM or every megabyte counts, Glances makes more sense. To quickly check the status, just SSH in and type glances. Netdata is perfect for those who want visuals and detail, but it's generous with RAM. Also, note that Netdata runs its own web server and database. Glances, on the other hand, is content with a simple HTTP server.
Conclusion
The undisputed winner in RAM consumption is Glances. The rich graphs and alarm system provided by Netdata require more resources. But everything depends on your needs. As someone who has been managing systems for 15 years, I can say: if you want a minimalist setup, choose Glances; if visuals matter to you, choose Netdata. Still, if you're undecided, try both and observe the RAM difference on your server.