Unable to start Java Virtual Machine with increased initial or maximum Java heap size setting
 Technote (troubleshooting)
 
Problem(Abstract)
In IBM® WebSphere® Application Server, increasing the maximum Java™ heap size might prevent the Application Server from starting. The Java Virtual Machine (JVM) might not be able to allocate all of the memory specified by the Java maximum heap size parameter.
 
Resolving the problem
If you increase the initial or maximum Java heap size values for the Application Server, you may encounter the following errors in the standard error log:
Unable to alloc heap of requested size, perhaps the maxdata value is too small - see README.HTML for more information.
**Out of memory, exiting**


Unable to mmap Java heap of requested size, perhaps the maxdata value is too large - see Java README.HTML for more information.

These error messages could be an indication that the MAXDATA value is set too low or too high.

To address this problem, change the MAXDATA value using the following command when more than 1GB is used by the JVM.

export LDR_CNTRL=MAXDATA=0xn0000000
(n segments)

Refer to the following document for the recommended n segments value for your environment:
Running your Java application on AIX, Part 2: JVM memory models
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Java SDK
Operating system(s): AIX
Software version: 5.0
Software edition:
Reference #: 1177317
IBM Group: Software Group
Modified date: Mar 31, 2006