Enable 32-bit Linux/CentOS to support 4 GB memory or above

Enable 32-bit Linux/CentOS to support 4 GB memory or above

Let the 32-bit CentOS System Support 4 GB memory or above. At the beginning, some people said that 64-bit systems are not all solved? In fact, 32-bit systems and 64-bit systems have their respective functions. The following uses a CentOS-5.5-32 bit for demonstration.

I. system environment:
Vmwarevm

System: Centos-5.5 32-bit
Memory: 4 GB
The 32-bit system does not lift the limit, and the system can only recognize 3 GB memory.
# Free-m

# Uname-a // original Kernel
Linux localhost 2.6.18-194. el5 #1 SMP Fri Apr 2 14:58:35 EDT 2010 i686 i686 i386 GNU/Linux

Ii. Install PAE (physical address extension)
# Rpm-qa | grep kernel-PAE // check whether the kernel-PAE-devel and kernel-PAE packages are installed. For installation, view the grub boot configuration file.
# Yum-y install kernel-PAE *
# Vim/boot/grub. conf

Default = 0 // Change 1 to 0 and start PAE. Otherwise, the operation fails.
Timeout = 5
Splashimage = (hd0, 0)/grub/splash.xpm.gz
Hiddenmenu
Title CentOS (2.6.18-371.11.1.el5PAE) // install PAE.
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 // restart the system
# Free-m // check that the memory already supports 4 GB or above

If the restart error is reported or the memory is not changed, it is estimated that the hardware on your server is not supported...

# Uname-a // view the current Kernel
Linux localhost 2.6.18-371.11.1.el5PAE #1 SMP Wed Jul 23 15:54:19 EDT 2014 i686 i686 i386 GNU/Linux