eclipse.ini

Overview

Eclipse startup is controlled by the options in $ECLIPSE_HOME/eclipse.ini. If $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.

Important:

You can, and should, experiment with changes to the launch command from your Command Prompt/Terminal before changing the eclipse.ini itself.
Each option and each argument to an option must be on its own line.
All lines after -vmargs are 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)
Any use of -vmargs on the command-line replaces all -vmargs settings in the .ini file unless --launcher.appendVmargs is specified either in the .ini file or on the command-line. (doc)
-XX VM arguments are subject to change without notice, even during minor updates. If the JVM keeps exiting with code 2 instead of starting Eclipse, try removing them.
Make a backup--keep a copy of the original contents on hand so you don't break your installation and have to download it all again.

By default, 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

Specifying the JVM

Eclipse runtime options

Each line before -vmargs contains an option followed by the value for option. All the lines after -vmargs are passed as JVMarguments, so all options andarguments for eclipse startup must be specified before -vmargs. For example -vm settings for JDK to be used.