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In Windows 32 bit I have the /pae option to use up to 4 GB of RAM for example as a ram disk. Can I configure Linux 32 bit the same way? What option do I need to select in the kernel config menu to enable /pae? When I start top in Linux 32 bit I can only see a total of 2 GB of ram? Does Linux uses up to 4 GB when I install the 64 bit version?

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up vote 5 down vote accepted

You need to install and boot the PAE kernel. If you are using Red Hat or one of it's derivatives, yum install kernel-PAE.

If the RPM doesn't do it for you, you'll want to set the default grub entry to the PAE kernel in /etc/grub.conf.

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Is this a kernel module or something? Can I compile it myself? – Betterdev Dec 29 '11 at 21:50
It's an actual kernel not a module. There's no need to compile if your distribution already packages the binary. (Unless you have the need to build it with non-default options.) – Aaron Copley Jan 3 '12 at 22:00

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