While running my Minecraft server, I noticed the following message outputted in the console.

24.01 02:11:04 [Server] INFO Warning, your max perm gen size is not set or less than 128mb.
It is recommended you restart Java with the following argument: -XX:MaxPermSize=128M

I was wondering what exactly the max perm gen size is, and more importantly, how can I restart Java via command line with this argument? I tried searching for how to restart Java, but there does not seem to be any documentation on how to do this via command line.

1 Answer 1


PermGen space is used for things that do not change (or change often). e.g. Java classes. So often large, complex apps will need lots of PermGen space.

Source: http://rimuhosting.com/knowledgebase/linux/java/-Xmx-settings

If minecraft is started with a shell script, look for a line that looks something like this:

java -Xmx1024M -Xms1024M -jar minecraft_server.jar nogui

Add a new java configuration setting for the max perm size:

java -Xmx1024M -Xms1024M -XX:MaxPermSize=128M -jar minecraft_server.jar nogui

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