FIX: Minecraft server could not reserve enough space

Tashreef Shareef
by Tashreef Shareef
Windows & Software Expert
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  • Minecraft is one of the most popular sandbox games that you can play across platforms. It also allows users to create their own server to play with friends.
  • However, at times while allocating more space to your Minecraft server or accessing the server, you may encounter the could not reserve enough space error.
  • For more great articles about this amazing voxel game, check out our dedicated Minecraft hub.
  • Visit our detailed Gaming section to learn and fix more Minecraft and other gaming-related issues.
Minecraft server couldn't reserve enough space

It is always beneficial to add more RAM to your Minecraft server. However, at times while adding more RAM or allocating more space, you may encounter the could not reserve enough space for object heap. This error can occur due to incorrect version of Java JRE.

Several users have reported similar errors in the Reddit community forum.

I hope this is the right sub-reddit anyway, i am making a survival server with my friends and when i add more ram i am getting this error
C:UsersmeandDesktopServer>java -Xmx2048M -Xms2048M -jar server.jar nogui
Error occurred during initialization of VM

Could not reserve enough space for 2097152KB object heap
C:UsersmeandDesktopServer>PAUSE
Press any key to continue . . .

If you are also troubled by this error, here are a couple of troubleshooting tips to help you resolve the Minecraft server could not reserve enough space issues in Windows.


How do I fix the could not reserve enough space Minecraft error?

1. Install 64-bit Java JRE

could not reserve enough space

  1. Go to the Java JRE download page.
  2. Click on Windows Offline (64-bit). Wait for the download to complete.
  3. Double-click on the Java installer to install the 64-bit edition of the Java runtime environment.
  4. Launch your Minecraft server and try to allocate more RAM to the server.
  5. Check if the could not reserve enough space error is resolved.

If the issue persists even after installing the 64-bit version of Java JRE, follow these steps.

    1. Press Windows Key + R to open Run.
    2. Type cmd and click OK to open Command Prompt.
      could not reserve enough space
    3. In Command Prompt, type the following command and click OK:
      java -version 
    4. The above command will display the Java version installed on your computer. The result will look something like this:
      C:>java -version
      java version "1.8.0_221"
      Java(TM) SE Runtime Environment (build 1.8.0_221-b11)
      Java HotSpot(TM) 64-Bit Server VM (build 25.221-b11, mixed mode)
    5. If it doesn’t say “64-bit Server VM”, it means Minecraft is still finding the 32-bit version.
    6. To fix this, you need to remove the older version and reinstall the 64-bit edition again.

Remove and reinstall 64-bit Java JRE

could not reserve enough space

  1. Press Windows Key + R.
  2. Type appwiz.cpl and click OK to open Control Panel.
  3. Choose the 32-bit edition of Java and click on Uninstall.
  4. Also, uninstall Java JRE 64-bit edition.
  5. Once done, install the 64-bit Java JRE downloaded in the first step.
  6. Try allocating more space to your Minecraft server and check for any improvements.

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2. Add a new system variable

Note: Before proceeding with the below steps, create a system restore point.

could not reserve enough space

  1. Press Windows Key + R to open Run.
  2. Type control and click OK to open Control Panel.
  3. Go to System and Security > System.
  4. Click on View advanced system settings from the left pane.
  5. In the System Properties window, click on the Environmental Variables button.
    Java Minecraft RAM error
  6. Under the System Variables section, click the New button.
    Java Minecraft RAM error
  7. Enter the following for Variable name and value:
    Variable name: _JAVA_OPTIONS
    Variable value: Xmx512M
  8. Click OK to save the changes.
  9. Click OK on all the open Windows.

The above process will set the memory size to 512MB and fix the could not reserve enough space Minecraft server error.

The Minecraft server could not reserve enough space error can be resolved by installing the 64-bit edition of Java JRE. Since the 32-bit edition is limited on the memory front, installing the 64-bit edition of Java will remove the limitation.

However, if the error occurs without making any changes, try limiting the memory allocation to 512MB by adding a new system variable in Control Panel.

FAQs: Learn more about Minecraft and Java JRE space allocation

  • Can I use VPNs with Minecraft?

Yes, VPN should not hinder your connectivity to Minecraft. However, if you are encountering issues, check out this article on troubleshooting Minecraft connectivity via VPNs.

  • Does Minecraft need updates?

Yes, Minecraft is updated regularly. Check out this guide on how to update Minecraft for Windows 10.

  • Do I have to pay to play on Minecraft servers?

Besides the one-time fee of purchasing Minecraft, users also have to pay a subscription in order to play online on the official servers. However, you can follow this article to see how you can create servers for you and your friends for free.