JVM 崩溃 Failed to write core dump解决办法 WINDOWS

MIT
key words: JVM,崩溃，windows，Failed，core dump，虚拟内存

最*从*台中分出了一个小项目，没有配置单独的服务器，而是需要部署到公司网站服务器（windows server）上去。
一共部署一个网站，一个设备通信服务jar
阿里云ECS 4G 内存，系统：windows server 2008 SP1 64位未激活

一开始查看了下java环境变量，设置得非常乱，上面装了两个java，一个64位一个32位，但是path指向的都是32位的java。

通信服务jar能够顺利启动，不过隔三差五就挂掉，报JVM异常

tomcat 一开始启动就不顺利，重新设定了JAVA_HOME才启动，后来也没过几天又挂掉了，后来再也启动不了了。。。。。

当时直接在bin目录生成的日志hs_err_pid1234.log内容是：

#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (malloc) failed to allocate 32744 bytes for ChunkPool::allocate
# Possible reasons:
#   The system is out of physical RAM or swap space
#   In 32 bit mode, the process size limit was hit
# Possible solutions:
#   Reduce memory load on the system
#   Increase physical memory or swap space
#   Check if swap backing store is full
#   Use 64 bit Java on a 64 bit OS
#   Decrease Java heap size (-Xmx/-Xms)
#   Decrease number of Java threads
#   Decrease Java thread stack sizes (-Xss)
#   Set larger code cache with -XX:ReservedCodeCacheSize=
# This output file may be truncated or incomplete.
#
#  Out of Memory Error (allocation.cpp:273), pid=2620, tid=4872
#
# JRE version: Java(TM) SE Runtime Environment (8.0_45-b15) (build 1.8.0_45-b15)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.45-b02 mixed mode windows-amd64 compressed oops)
# Failed to write core dump. 
....以下省略超多jvm异常

不外乎说内存不够，64位的OS 没有用64位的java，减少java 线程数，等等之内的，但是我看了下任务管理器，线程数也不多，4G物理内存，才用了1.2G

没办法，只好把java全部卸载，重新安装64位版本的。重新设定JAVA_HOME和PATH，发挥JAVA最大功效。还是没好，然后又把盗版系统激活重新，还是没好

最后，我在通过运行DxDiag 查看系统信息时才发现问题：

一开始的System Information：

------------------
Time of this report: 12/15/2015, 13:54:13
       Machine name: iZ23leuxxxxx
   Operating System: Windows Server 2008 R2 Standard 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.130708-1532)
           Language: Chinese (Simplified) (Regional Setting: Chinese (Simplified))
System Manufacturer: Xen
       System Model: HVM domU
               BIOS: Revision: 1.221 
          Processor: Intel(R) Xeon(R) CPU E5-2430 0 @ 2.20GHz (2 CPUs), ~2.2GHz
             Memory: 4096MB RAM
Available OS Memory: 4096MB RAM
          Page File: 3908MB used, 184MB available
        Windows Dir: C:Windows
    DirectX Version: DirectX 11
DX Setup Parameters: Not found
   User DPI Setting: Using System DPI
 System DPI Setting: 96 DPI (100 percent)
    DWM DPI Scaling: Disabled
     DxDiag Version: 6.01.7601.17514 32bit Unicode

------------

其中Page File: 3908MB used, 184MB available ，184M，太小了，然后到C盘查看隐藏文件，居然没发现pagefile.sys文件。
也就是没有设置虚拟内存。。。。。

设置完虚拟内存后：

Time of this report: 12/15/2015, 14:07:22
   Machine name: iZ23leuxxxxx
   Operating System: Windows Server 2008 R2 Standard 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.130708-1532)
           Language: Chinese (Simplified) (Regional Setting: Chinese (Simplified))
System Manufacturer: Xen
       System Model: HVM domU
               BIOS: Revision: 1.221 
          Processor: Intel(R) Xeon(R) CPU E5-2430 0 @ 2.20GHz (2 CPUs), ~2.2GHz
             Memory: 4096MB RAM
Available OS Memory: 4096MB RAM
          Page File: 4486MB used, 6703MB available
        Windows Dir: C:Windows
    DirectX Version: DirectX 11
DX Setup Parameters: Not found
   User DPI Setting: Using System DPI
 System DPI Setting: 96 DPI (100 percent)
    DWM DPI Scaling: Disabled
     DxDiag Version: 6.01.7601.17514 32bit Unicode