How to get 4gb of ram working in Ubuntu 32bit version

How to get 4gb of ram working in Ubuntu 32bit version... edited, be sure you read the end of the article

 

Recently I decided to upgrade the RAM memory of my Laptop to 4 GB. I was running my Ubuntu Jaunty 32 bit version with only 2 GB and it was clear that is was not enough to run my virtual machines in it.

 

I decided to buy 4 GB and install the memory, the installation went fine and the 4 GB of ram got detected properly in my BIOS settings. After checking  my Ubuntu System Monitor and also by running in the terminal the "$ free" command, I realized that my 9.04 Desktop version was only showing me 3 GB of ram.... after googling I found that it was a limitation of 32 bit systems.

$ free
total       used       free     shared    buffers     cached
Mem:       4053920    1133536    2920384          0      99908     428480
-/+ buffers/cache:     605148    3448772
Swap:      2208896          0    2208896

The solution:

A simple line that installs the server kernel in the Desktop version. This way, even though I'm running the 32bit desktop version, the kernel is actually the 9.04 server version.

Works fine ;) and I'm getting 4 GB of ram. To achieve this here are the commands:

 

sudo apt-get update
sudo sudo apt-get install linux-headers-server linux-image-server linux-server

 

SOLVED WITH 9.10 KARMIC KOALA

Using the Update Manager I had the opportunity of upgrading from 9.04 to 9.10... even thought I was using server kernel the update went without problems and the new 9.10 32bit kernel comes with PAE support. Because I wanted to replace my hard Drive (160gb / 5400rpm) with a (500gb / 7200 rpm) I decided to backup my home folder (40gb) and make a fresh, clean 64bit install. So right now I'm running Ubuntu 9.10/64 Karmic Koala in my beautiful laptop with 4gb ram and a 500gb / 7200 rpm hard drive.