If the JVM needs more heap than it currently has, it will expand the heap in increments but will not exceed the maximum.
You can specify the number of bytes directly or use the suffix "MB" to indicate megabytes, for example, specifying "16MB" is the same as specifying "16777216."
Valid Values are Size in bytes OR MB
Example : JavaMinHeapSize=4096 or JavaMinHeapSize=4mb
This setting in new in ND6