Home/ Questions/Q 8645525
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-12T12:34:24+00:00

Sorry for asking the question, should have searched a bit more. Im running weka

  • 0

Sorry for asking the question, should have searched a bit more.

Im running weka with a rather large dataset and a memory intesive algoithm. I need all the heap space I cant get!

This works:

java -jar -Xmx2048m weka.jar &

But this does not

java -jar -Xmx4096m weka.jar &

I get:

Error occurred during initialization of VM Could not reserve enough 
space for object heap Could not create the Java virtual machine.

By some quick searching I found that this is the upper limit

java -jar -Xmx2594m weka.jar &

I have 4GB ram but a 32 bit machine. Why can’t I use 2^32 bytes = 4096MB of memory?

For the future I am wondering if I can run java with e.g. hundreds of GB of heap space if I have the correct hardware and OS?

I have both 1.6 and 1.7 JVM installed:

$java -showversion
java version "1.6.0_24"
OpenJDK Runtime Environment (IcedTea6 1.11.4) (6b24-1.11.4-1ubuntu0.12.04.1)
OpenJDK Server VM (build 20.0-b12, mixed mode)
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I have 4GB ram but a 32 bit machine. Why can’t I use 2^32 bytes = 4096MB of memory?
    For the future I am wondering if I can run java with e.g. hundreds of GB of heap space if I have the correct hardware and OS?

    For 4 GB I suggest you use a 64-bit OS and possibly a 64-bit JVM as the limit for the heap size can be as small as 1.2 GB (on Windows XP)

    If you want larger JVMs I suggest making sure you have 64-bit OS and JVM and you have more memory than the size of the JVM. e.g. if you want a 40 GB heap you need something like 48 GB or 64 GB of memory.

    • 0