I was getting "Invalid initial heap size: -Xms=1024M" piece starting JVM too fifty-fifty afterwards changing maximum heap size from 1024 to 512M it proceed crashing yesteryear telling "Invalid initial heap size: -Xms=512m , Could non practise the Java virtual machine". I cheque close everything starting from checking how much physical retentivity my machine has to whatsoever typo inwards JVM parameters, alone to notice out that instead of M, I had pose MB there. Java accepts both modest illustration too the majuscule illustration for Kilo, Mega, too Gigs. y'all tin usage one thousand or M, g or G etc but never used MB, GB or KB. Similar occupation tin occur alongside maximum heap size specified yesteryear -Xmx. Also from Java vi update 18, at that topographic point is alter on default heap size inwards JVM.
Invalid initial too maximum heap size inwards JVM
Here is a listing of mutual errors piece specifying maximum too minimum heap size inwards Java :
java -Xmx4056M -Xms4056M HelloWorld
Issue: Error occurred during initialization of VM , The size of the object heap + VM information exceeds the maximum representable size
Cause: the value of either -Xms or -Xmx is higher than or around the size of physical memory, every bit my machine has 4GB memory.
java -Xmx1056M -Xms2056M HelloWorld
Issue: Error occurred during initialization of VM , Incompatible minimum, too maximum heap sizes specified
Cause: value of -Xms is higher than -Xmx
java -Xms2056M HelloWorld
Issue: Error occurred during initialization of VM , Could non reserve plenty infinite for object heap
Cause: Only -Xms was provided too -Xmx was non provided. y'all volition also teach this mistake if y'all conduct maintain a typo too instead of -Xmx y'all conduct maintain specified -Xms 2 times, happened to my friend final time.
Command: java -Xms1024 yard -Xmx1024M HelloWorld
Issue: Error occurred during initialization of VM , Too modest initial heap
Cause: If y'all had infinite betwixt 1024 too yard than JVM assumes the size of -Xms every bit 1024 bytes alone too impress mistake that it's every bit good modest for JVM to start.
Invalid heap size
Another scenario when "invalid heap size" issue comes piece restarting JVM is, when y'all configure 64 fight JVM to convey retentivity to a greater extent than than 4GB but its running on 32 fight information model. This "invalid heap size" occurs especially inwards Solaris box where J2SE installation continas both 32 fight too 64 fight J2SE implementation. On other environs similar Windows too Linux 32 fight too 64 fight JVM are installed separately. 64 fight JVM installed on Solaris machines runs alongside 32 fight model if y'all don't specify either -d32 or -d64, which won't convey Maximum heap size of 4GB, thence "invalid heap size". You tin resolve this effect yesteryear running Solaris JVM alongside alternative -d64. -d64 ascendence business alternative allows JVM to usage 64 fight information model if available.public class HelloWorld{ public static void main(String args[]){ System.out.println("HelloWorld to Java"); } }
$ test@nykdev32: coffee -version coffee version "1.6.0_14" Java(TM) SE Runtime Environment (build 1.6.0_14-b08) Java HotSpot(TM) Server VM (build 14.0-b16, mixed mode) $ test@nykdev32: coffee -Xmx4096M HelloWorld Invalid maximum heap size: -Xmx4096M The specified size exceeds the maximum representable size. Could non practise the Java virtual machine. $ test@nykdev32: coffee -d64 -Xmx4096M HelloWorld HelloWorld to Java
If y'all run Java plan from ascendence business too so y'all volition also teach message tell Could non practise the Java virtual machine with each of invalid heap mistake but if y'all run your plan from Eclipse y'all volition non teach message "Could non practise the Java virtual machine", instead, y'all volition merely run across mistake message inwards console.
Regarding default heap size inwards Java, from Java vi update xviii at that topographic point are pregnant changes inwards how JVM calculates default heap size inwards 32 too 64-bit machine too on customer too server JVM mode:
1) Initial heap infinite too maximum heap infinite is larger for improved performance.
2) Default maximum heap infinite is 1/2 of physical retentivity of size upward to 192 bytes too 1/4th of physical retentivity for size upward to 1G. So for 1G machine maximum heap size is 256MB 2.maximum heap size volition non move used until plan creates plenty object to fill upward initial heap infinite which volition move much lesser but at-least 8 MB or 1/64th purpose of Physical retentivity upward to 1G.
3) For Server Java virtual machine default maximum heap infinite is 1G for 4GB of physical retentivity on a 32 fight JVM. for 64 fight JVM its 32G for a physical retentivity of 128GB.
Further Learning
Java Memory Management
How Garbage collection industrial plant inwards Java