Before you proceed with JavaTM Virtual Machine tuning, it is important to note the following:
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 Foglight® 5 is a Java application that ships with and uses the Oracle® Java Hotspot Virtual Machine (JVM). While there are other vendors of JVMs, the Oracle JVM should not be replaced or altered.  | 
This section provides information on how to tune the JVM to achieve maximum performance.
The following factors heavily impact JVM utilization:
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 the length of the time period for which Foglight® is configured to preserve historical data about observations   | 
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To review or modify Foglight® JVM configuration options, locate the following file:
Foglight reads JVM options from values of server.vm.optionsX properties, where X is a number from 0 to 99.
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 The JVM options currently in effect (the default Foglight JVM options, server.config settings, and command line arguments) are all logged in the server log file during startup.  | 
The following table describes the most commonly used Oracle® Hotspot JVM options: