When Starting The JVM In Java, What Do The -xms And -xmx Parameters Represent?

The -Xms and -Xmx parameters are used when starting the Java Virtual Machine (JVM) to specify the initial and maximum heap memory sizes, respectively.

  • -Xms sets the initial heap size for the JVM. It defines the amount of memory that will be allocated to the JVM at startup. For example, if you set -Xms512m, the JVM will start with an initial heap size of 512 megabytes.

  • -Xmx sets the maximum heap size for the JVM. It defines the upper limit of memory that can be used by the JVM. For example, if you set -Xmx1024m, the JVM will not be allowed to use more than 1024 megabytes of memory.

It’s worth noting that the JVM uses a garbage collector to free up memory, so the actual memory usage might be lower than the specified maximum heap size. However, if the specified maximum is reached and the garbage collector is unable to free up enough memory, an OutOfMemoryError will occur.

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