What this error means
The "Could not reserve enough space for object heap" error occurs when the Java Virtual Machine (JVM) fails to allocate the amount of RAM requested in the startup command. This usually happens because the host machine has insufficient physical memory available, or the operating system is restricting the process from accessing the requested heap size.
How to fix it
On AwakeNode
- Check your plan: If your server is hitting its memory limit, you may need to upgrade your hosting plan. On AwakeNode, upgrading your plan automatically updates your Xmx settings, so no manual configuration is required.
- Contact Support: If you believe your server has sufficient RAM but is still throwing this error, open a ticket with our support team. To add your own JVM flags, set a custom startup command in your server's Startup tab.
On other hosts / manually
- Reduce Xmx: Locate your server's startup script or command line. Look for the
-Xmxflag (e.g.,-Xmx4G). Reduce this value to a lower amount that fits within your available system memory. - Check 32-bit vs 64-bit Java: Ensure you are running a 64-bit version of Java. A 32-bit Java installation cannot address more than approximately 1.5GB to 2GB of RAM, which often triggers this error if you attempt to allocate more.
- Review other processes: Ensure that other applications running on the same machine are not consuming the memory required by your Minecraft server.
Questions
Why does my server crash with this error even if I have enough RAM?
This often happens if you are using a 32-bit version of Java, which has a strict memory limit regardless of how much RAM your computer has.