What the CPU, memory and disk numbers on your server mean

The panel shows a few live numbers next to your console: CPU, memory, disk and network. They're useful, but only if you know how to read them. A few of them behave in ways that surprise people.

CPU: 100% is one core, not everything

The CPU figure is measured against a single core. 100% means one full core in use, 200% means two cores, and so on. So a server on a plan with two cores can legitimately show 150% and be perfectly healthy.

What you care about is how that number compares with your plan's CPU allowance, and whether it stays pinned there. A short spike when a player joins or a world loads is normal. A server that sits at its limit all the time is one that will lag.

One thing worth knowing: Minecraft mostly runs on one main thread. So even on a multi-core plan, the server can lag with CPU "looking fine" overall, because that one thread is the bottleneck. That's why upgrading cores doesn't always cure lag. See How to fix server lag.

Memory: used, not wasted

Memory shows how much you're using against your plan's limit. Two points:

  • Programs like Java use whatever they're given, so a bar close to the limit is not a problem on its own. Watch the trend, not a single reading.
  • If the number reaches the limit and the server stops with no error, it ran out of memory. For Minecraft, Minecraft server out of memory walks through it.

Disk: the quiet one that breaks things

Disk fills up slowly and then suddenly causes odd problems: worlds not saving, plugins failing to write files, or No space left on device in the console. Check it occasionally.

When it's getting full, look in the file manager for:

  1. Old logs. The logs folder keeps a compressed file per session. Delete the oldest.
  2. Crash reports. The crash-reports folder adds up if the server has been crashing.
  3. Map and plugin data. Web-map plugins can create enormous amounts of tile images.
  4. Unused worlds. Old copies of worlds you tried and abandoned.

Download anything you might want first, since deleting is permanent. Take a backup before you remove anything you aren't sure about.

Network

The network numbers show data sent and received. They're handy for spotting something unexpected, like heavy outgoing traffic when nobody's online, but they won't tell you much about lag. A server with a poor connection to its players shows up as high ping, not high network usage.

A habit worth building

When your server is running well, glance at these numbers and remember what they look like. When something goes wrong, you'll know straight away what's different. Without that, a graph is just a shape.

Still stuck? Open a ticket on Discord - run /ticket in any channel, pick a department, and include your Server ID or Invoice ID so we can jump straight in.