I have a Windows 7 laptop, with 16GB RAM. When I run multiple java servers I get OutOfMemory error, however, windows task manager shows that I still have 6GB of free physical memory left. It seems like to me that my JVM can only allocate ~2GB heap for all running java apps.
So I wrote some very simple Java code:
public class HelloWorld {
public static void main(String[] args) {
for(;;) System.out.println("Hello, World");
}
}
My -jvm version:
$ java -version
java version "1.8.0_111"
Java(TM) SE Runtime Environment (build 1.8.0_111-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)
JAVA_HOME "C:\Program Files\Java\jdk1.8.0_111"
JRE_HOME "C:\Program Files\Java\jre1.8.0_111"
I did a simple java -Xmx256m -Xms256m HelloWorld and it worked as expected, however when I switched to java -Xmx2048m -Xms2048m HelloWorld I get the following:
Error occurred during initialization of VM
Could not reserve enough space for object heap
I tried multiple JDKs but none of them are working. Both windows and JVM are in 64 bits.
What can I do to fix this problem?
It seems like to me that my JVM can only allocate ~2GB heap for all running java apps.
That is not correct. The JVM is capable of asking for and using a >2GB heap.
It must be that Windows is restricting what the Java process can ask for. It may also be that Windows has reserved memory for multiple Java processes, but the memory is showing as free because the JVMs have not used it.
FWIW, running JVMs with lots more memory than they really need is not a good idea.
The fix?
Don't do it. Don't run lots of 2GB Java servers on your laptop, or reduce the heap size to something more reasonable. Overcommitting your memory is an attractive idea, until the JVMs start using all of the memory that you have allocated them. Then your system thrashes ...
Do it differently. You can run multiple servers in a single JVM.
Get more memory.
Just don't use -Xms2048m. It makes JVM to request a continuous 2Gb block of memory at once. Let JVM decide when to get additional mem for heap needs. In case of Windows, the effect you observe may be the result of badly aligned dlls mapped to proc virtual memory (antivirus, firewall, rootkit, virus etc), which make virtual memory fragmented. Running java from ide, using agents (with native impl) could also add hidden content to process virtual memory. A nice tool to observe a virtual memory of a process is vmmap from Microsoft Sysinternals suite
Related
There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (malloc) failed to allocate 1048576 bytes for AllocateHeap
# An error report file with more information is saved as:
# C:\jboss-eap-services-6.4.4\bin\hs_err_pid6632.log
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=256m;
support was removed in 8.0
With the problem above, I'm trying to start the jboss server. I tried some steps and I could not find the right solution.
Please use the following setting to allocate the memory for the permanent location -Xms1024m -Xmx1024m -XX:PermSize=512m -XX:MaxPermSize=512m -XX:-UseGCOverheadLimit
You can try to increase eclipse memory, you can do this in le eclipse.ini file (near eclipse executable file) or in the command line arguments :
-Xms256m
-Xmx16348m
It is JBoss (not Eclipse) that is crashing. So increasing Eclipse's memory is futile! (It might make things worse, in fact.)
The second thing to note is that you are running out of space in a native allocation request, so increasing the regular heap's size will not help. Options like the following will probably NOT help! (They might make things worse, in fact.)
-Xms1024m -Xmx1024m -XX:-UseGCOverheadLimit # USELESS
The third thing to note is that your JVM doesn't have a PermGen space, so fiddling with the PermGen size via
-XX:PermSize=512m -XX:MaxPermSize=512m # USELESS
is futile. (That is what Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=256m; support was removed in 8.0 is saying.)
So what is the real problem?
Well you are running a 64-bit JRE, so it is not an architectural problem. (On a 32-bit JRE, the JVM's address space has hard limits ...)
In fact, it is a problem outside of the JVM itself. Basically, the JVM has asked the OS for more memory, and the OS has said "Nope!". I can thing of two possible explanations:
There may be a per-process "ulimit" in place, that is restricting the process size. Your JVM has requested beyond that limit.
The OS may have run out of virtual address space or mappable virtual memory. The former is unlikely. The latter typically arises because your OS doesn't have enough RAM and/or swap space. This can also happen is you are running within a virtual machine that is ... less than generous endowed with memory resources.
Now it appears that this may be happening when the JVM is trying to grow the Java heap. But either way, the problem is not the size of the Java heap.
I've started seeing the following error using 32-bit (and 64 for that matter) Java 6 (on Windows 8 x64. This wasn't an issue until some Windows updates were installed.....) to call ant scripts
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
Anyone ever seen it before? I've done some digging around SO and other places and haven't come across anything that's solved this issue for
Edit 8/24
So far, here are the following things I have attempted to fix the issue, none of which have worked:
Setting _JAVA_OPTIONS in system environment variables, up to 3gb for the maximum heap size
Setting JVM_OPTS in cmd before invoking ant, again max heap size up to 3gb
Passing in -Xms and -Xmx arguments when making the actual java call, like so %JAVA_HOME%\bin\java -Xms512m -Xmx2048m org.apache.tools.ant.Main
Setting the ANT_OPTS variable before calling ant
Uninstalling Windows updates going back before these issues.
Does anyone have a solution that differs from the following? As the other attempts have not been working..
When you run on 32-bit windows (or in the 32-bit windows emulator) you have only about 1.2 GB - 1.5 GB of virtual memory available. This size depends on what else you might have running in that space as it doesn't always isolate programs from each other in terms of memory space (i.e. the memory space is limit and shared)
So after updating windows, it could have installed a new program which is run before Java, or updated an existing which is using more memory.
The simplest solution is to use a 64-bit JVM which doesn't have this problem. Or you have to reduce the maximum heap size.
Unable to set java heap space using -Xmx to 2GB or more even though the RAM size is 16GB.
I encounter an error saying "
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit"
This is seen while starting a Jenkins server on my Win2008 x64 machine.
Please let me know if I could change any system parameter which will allow me to allocate more memory.
Thanks
Run
java -version
and check you see
Java HotSpot(TM) 64-Bit Server VM (build 24.51-b03, mixed mode)
I expect you have a 32 bit version of java which is limited to 2 GB (as its not large address aware)
Found the fix with the help of clue given above by Neil.
Here is the full details:
Even though the machine is installed with JDK 1.7 x64 bit, Jenkins by default is not configured with this version available on the machine.
Jenkins has its own JRE bundled with the installer which is used by default.
To change it to a different JDK edit the Jenkins.xml file and modify the below value
<executable>jre\bin\java</executable>
to
<executable><jdk install path>\bin\java</executable>
This is now solved!!
Use "java -version" to ensure that your java hotspot is a 64-bit server vm.
theoretical limit for maximum heap size on 32 bit JVM is 4GB and for 64 bit JVM its 2^64
For more detail Click here
I want to run a memory intensive package on a web server.
Current computer's settings are...
Windows 7 64 bit
64-bit JVM
RAM: 8GB
When I try to run eclipse with
-Xms1024m -Xmx2048m -XX:MaxPermSize=256m
I get:
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
From posts that I read, it seems like I should be able to use more than 4GB of memory.
When I ran the code, I was able to max out the memory at -Xmx1200M and still be able to run the code. But for what I want to accomplish, I need to use more memory. How can I increase the memory size here?
Thank you everyone. The issue was that I was using a 32-bit version of JDK. I was able to run memory at 2GB after switching the JDK to the 64 bit version. Thanks!
The problem was that I was using a 32-bit version of JDK.
Thank you, and thank you to Mister Smith for pointing out that I should answer it and mark it as solved.
I am running server with 256MB RAM. Maximum heap size I can allocate for Java is 110MB. When I add those param to JAVA_OPTS I can run java -version. Problem is that I can not run Tomcat with these parameters. Maximum heap size for Tomcat to run is 40MB. I do not know why I can not allocate more memory?
Of course I get error:
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
Set CATALINA_OPTS to -Xmx110m, JAVA_OPTS. I suppose you could set both, to be sure.
The Xmx flag may be ignored when you run the java executable with the -version flag. This depends on how you pass the version flag. The following are the results on my machine with 2GB RAM:
Version flag passed before Xmx
C:\Users\Reynolds>java -version -Xmx10240M
java version "1.6.0_21"
Java(TM) SE Runtime Environment (build 1.6.0_21-b07)
Java HotSpot(TM) Client VM (build 17.0-b17, mixed mode, sharing)
which is weird considering that 10G is beyond the max addressable limit on memory in a 32-bit environment.
Version flag passed after Xmx
C:\Users\Reynolds>java -Xmx10240M -version
Invalid maximum heap size: -Xmx10240M
The specified size exceeds the maximum representable size.
Could not create the Java virtual machine.
C:\Users\Reynolds>java -Xmx1524M -version
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
which is closer to reality.
You might want to verify how much contiguous memory is available to Java in reality, using the second approach, and then decide on an optimal value for the maximum heap size.
The error message suggests you do not have enough free RAM try closing other applications and seeing if you can allocate a larger heap then. You may need more RAM I am afraid.