Eclipse startup is controlled by the options in
$ECLIPSE_HOME is not defined, the default
eclipse.ini in your Eclipse installation directory (or in the case of Mac, the
Eclipse.app/Contents/MacOS directory) is used.
eclipse.ini is a text file containing command-line options that are added to the command line used when Eclipse is started up. There are many options available, please see here.
- Each option and each argument to an option must be on its own line.
- All lines after
-vmargsare passed as arguments to the JVM, so all arguments and options for eclipse must be specified before
-vmargs(just like when you use arguments on the command-line)
eclipse.ini looks something like this (the exact contents will vary based on operating system and which Eclipse package you have):
-startup ../../../plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar --launcher.library ../../../plugins/org.eclipse.equinox.launcher.cocoa.macosx.x86_64_1.1.100.v20110502 -product org.eclipse.epp.package.jee.product --launcher.defaultAction openFile -showsplash org.eclipse.platform --launcher.XXMaxPermSize 256m --launcher.defaultAction openFile -vmargs -Dosgi.requiredJavaVersion=1.5 -XX:MaxPermSize=256m -Xms40m -Xmx512m
Among other things, this sets the heap space to 40MB initially and a maximum of 512MB, and also specifies a maximum PermGen size of 256MB. A max heap of 512MB might be OK for some users, but it's often necessary to bump that value up for large project sets or when some third-party plugins are installed.
Specifying the JVM
One of the most recommended options to use is to specify a specific JVM for Eclipse to run on. Doing this ensures that you are absolutely certain which JVM Eclipse will run in and insulates you from system changes that can alter the "default" JVM for your system. Many a user has been tripped up because they thought they knew what JVM would be used by default, but they thought wrong. eclipse.ini lets you be CERTAIN.
The following examples of
eclipse.ini demonstrate correct usage of the -vm option.
Note the format of the -vm option - it is important to be exact:
- The -vm option and its value (the path) must be on separate lines.
- The value must be the full absolute or relative path to the Java executable, not just to the Java home directory.
- The -vm option must occur before the -vmargs option, since everything after -vmargs is passed directly to the JVM.
This is how the
-vm argument might look on Windows (your exact path to
javaw.exe could be different, of course):
This content would go near the bottom after other arguments:
-vm /opt/sun-jdk-1.6.0.02/bin/java -vmargs -Xms40m -Xmx512m
Mac OS X Example
On a Mac OS X system, you can find
eclipse.ini by right-clicking (or Ctrl+click) on the Eclipse executable in Finder, choose Show Package Contents, and then locate
eclipse.ini in the
MacOS folder under
To specify Java 6 for OS X (this content would go near the end of the file, after other arguments):
-vm /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home/bin/java -vmargs -Xms40m -Xmx512m
- FAQ How do I run Eclipse?
- FAQ How do I increase the heap size available to Eclipse?
- FAQ How do I increase the permgen size available to Eclipse?
This FAQ was originally published in Official Eclipse 3.0 FAQs. Copyright 2004, Pearson Education, Inc. All rights reserved. This text is made available here under the terms of the Eclipse Public License v1.0.