Q. I've
total 8 GB RAM installed in my dual boot Ubuntu Linux 8.10 (32 bit)
version HP workstation. But free -m command only shows 3291 (3G) memory.
How do I use 8GB RAM under Ubuntu Linux?
A. You
need to install Physical Address Extension (PAE) aware kernel under 32
bit Ubuntu Linux. It is a feature of x86 and x86-64 processors that
allows more than 4 Gigabytes of physical memory to be used in 32-bit
systems.
Without PAE kernel, you should see something as follows:
Check your present Memory
$ free -m
Sample output:
total used free shared buffers cached
Mem: 3291 801 2489 0 95 342
-/+ buffers/cache: 363 2927
Swap: 1906 0 1906
Install PAE enabled kernel
Open terminal and type the following command if you are using Ubuntu version Ubuntu v9.04 and earlier:
$ sudo apt-get update
$ sudo sudo apt-get install linux-headers-server linux-image-server linux-server
If you are using Ubuntu v9.10 (Karmic Koala) and above, enter:
$ sudo apt-get install linux-generic-pae linux-headers-generic-pae
Once kernel images installed, just reboot your workstation, type:
$ sudo reboot
After reboot, login into your system and type the following command to verify memory usage:
$ free -m
Sample output:
total used free shared buffers cached
Mem: 8105 1292 6812 0 38 483
-/+ buffers/cache: 770 7334
Swap: 1906 0 1906
