[[setup-installation]]
== Installation

After link:/download[downloading] the latest release and extracting it,
*elasticsearch* can be started using:

[source,sh]
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$ bin/elasticsearch
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Under *nix system, the command will start the process in the background.
To run it in the foreground, add the `-f` switch to it:

[source,sh]
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$ bin/elasticsearch -f
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ElasticSearch is built using Java, and requires at least
http://java.sun.com/javase/downloads/index.jsp[Java 6] in order to run.
The version of Java that will be used can be set by setting the
`JAVA_HOME` environment variable.

.*NIX
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There are added features when using the `elasticsearch` shell script.
The first, which was explained earlier, is the ability to easily run the
process either in the foreground or the background.

Another feature is the ability to pass `-X` and `-D` directly to the
script. When set, both override anything set using either `JAVA_OPTS` or
`ES_JAVA_OPTS`. For example:

[source,sh]
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$ bin/elasticsearch -f -Xmx2g -Xms2g -Des.index.store.type=memory
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