Allows 32-bit Linux/centos system to support more than 4G of memory

Let the 32-bit CentOS system support more than 4G of memory, at the beginning of some people say that the 64-bit system is not solved it? In fact, 32-bit systems and 64-bit systems each have their own use. Below use centos-5.5-32 bit demo

First, the system environment:

VMware virtual Machines

System: Centos-5.5 32-bit

Memory: 4G

32-bit system does not break the limit, the system can only recognize 3G of memory

# free-m

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# uname-a //RAW kernel

Linux localhost 2.6.18-194.el5 #1 SMP Fri Apr 2 14:58:35 EDT i686 i686 i386 gnu/linux

Second, install PAE (Physical Address Extension)

# Rpm-qa | grep kernel-pae//See if Kernel-pae-devel and KERNEL-PAE packages are installed, such as installing to view the Grub boot profile directly

# yum-y Install kernel-pae*

# vim/boot/grub/grub.conf

default=0//Change 1 to 0, boot up PAE, otherwise unsuccessful

Timeout=5

Splashimage= (hd0,0)/grub/splash.xpm.gz

Hiddenmenu

Title CentOS (2.6.18-371.11.1.EL5PAE) //install PAE, see this line means you're successful.

Root (hd0,0)

Kernel/vmlinuz-2.6.18-371.11.1.el5pae ro root=label=/rhgb quiet

Initrd/initrd-2.6.18-371.11.1.el5pae.img

Title CentOS (2.6.18-194.EL5)

Root (hd0,0)

Kernel/vmlinuz-2.6.18-194.el5 ro root=label=/rhgb quiet

Initrd/initrd-2.6.18-194.el5.img

# init 6 //reboot system

# free-m //view memory has supported more than 4G

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If the restart error or memory is not changed, then it is estimated that your server hardware does not support ...

# uname-a //view current use kernel

Linux localhost 2.6.18-371.11.1.el5PAE #1 SMP Wed Jul 15:54:19 EDT i686 i686 i386 gnu/linux