Which arguments stand for what in JVM memory options?

Question

There a lot of JVM arguments that affect the JVM\'s memory usage like -Xms, -Xmx, -Xns, -XX:MaxPermSize...

• What do they do?
• Are there any

Answer 1

There are hundreds of JVM options available. Basically they are classified into three types:

1. Standard Options,
2. Non-standard X options,
3. Non-standard XX options,

List of few standard options: [To see complete list execute the command "java" without any option]

 -client       to select the "client" VM
 -server       to select the "server" VM
 -cp 
 -classpath 
               A ; separated list of directories, JAR archives,
               and ZIP archives to search for class files.
 -D=
               set a system property
 -version      print product version and exit
 -showversion  print product version and continue
 -X            print help on non-standard options`

List of few non-standard X options: [To see complete list execute the command "java -X"]

-Xincgc           enable incremental garbage collection
-Xms        set initial Java heap size
-Xmx        set maximum Java heap size
-Xss        set java thread stack size
-Xprof            output cpu profiling data
-Xmixed           mixed mode execution (default)
-Xint             interpreted mode execution only

List of few non-standard XX options: [Complete list available here]

-XX:InitialHeapSize=        set initial Java heap size. Same as -Xms.
-XX:MaxHeapSize=            set maximum Java heap size. Same as -Xmx.
-XX:+PrintFlagsFinal              prints all JVM options passed.
-XX:+UnlockDiagnosticVMOptions    opens up lot more VM options.

If you want to enhance your knowledge in JVM options, please refer this blog. The link is just part 1 out of 8. Find out and read other parts as well.