如何让linux/Centos 32位支持8G内存?内核安装PAE支持大于4GB内存的方法。linux/Centos 32bit OS 默认不支持4G以上内存的，自己怎么没想到，Baidu了一下，找到了解决方法，安装一个kernel-PAE补丁就可以了，下面是几个步骤：
[root@www.ctohome.com]# free
total used free shared buffers cached
Mem: 3881968 637928 3244040 0 111292 461680
-/+ buffers/cache: 64956 3817012
Swap: 4192924 0 4192924
[root@www.ctohome.com]# yum install kernel-PAE
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
centos-burstnet | 1.1 kB 00:00
updates-burstnet | 1.9 kB 00:00
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package kernel-PAE.i686 0:2.6.18-194.32.1.el5 set to be installed
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================================================================================================================
Package Arch Version Repository Size
================================================================================================================================================================================
Installing:
kernel-PAE i686 2.6.18-194.32.1.el5 updates-burstnet 17 M
Transaction Summary
================================================================================================================================================================================
Install 1 Package(s)
Upgrade 0 Package(s)
Total download size: 17 M
Is this ok [y/N]: y
Downloading Packages:
kernel-PAE-2.6.18-194.32.1.el5.i686.rpm | 17 MB 00:01
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : kernel-PAE 1/1
Installed:
kernel-PAE.i686 0:2.6.18-194.32.1.el5
Complete!
[root@www.ctohome.com]# free
total used free shared buffers cached
Mem: 3881968 637928 3244040 0 111292 461680
-/+ buffers/cache: 64956 3817012
Swap: 4192924 0 4192924
[root@www.ctohome.com]# vi /boot/grub/grub.conf
default=0 （把default=1改成default=0）
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.18-194.32.1.el5PAE) （有这行PAE的就表示安装pae内核成功）
root (hd0,0)
kernel /vmlinuz-2.6.18-194.32.1.el5PAE ro root=LABEL=/
initrd /initrd-2.6.18-194.32.1.el5PAE.img
title CentOS (2.6.18-194.32.1.el5)
root (hd0,0)
kernel /vmlinuz-2.6.18-194.32.1.el5 ro root=LABEL=/
initrd /initrd-2.6.18-194.32.1.el5.img
title CentOS (2.6.18-194.el5)
root (hd0,0)
kernel /vmlinuz-2.6.18-194.el5 ro root=LABEL=/
initrd /initrd-2.6.18-194.el5.img
[root@www.ctohome.com]# reboot （这里重启服务器，祈祷吧，有时候主板或网卡不支持，那么就只能联系机房了）
Broadcast message from root (pts/0) (Thu May 19 18:52:34 2011):
The system is going down for reboot NOW!
[root@www.ctohome.com]# free
total used free shared buffers cached
Mem: 8295488 215248 8080240 0 19460 142592
-/+ buffers/cache: 53196 8242292
Swap: 4192924 0 4192924