Archive for July, 2009

I think most people would agree with me that 64 bit Linux is not the greatest desktop right now. In fact 64 bit Operating Systems in general are out performed by 32 bit until you start to get into ram sizes above 4GB where native physical address extension will top out the 32 bit added physical address extension. Even then the 32 bit applications run faster so unless you are planning on running a enterprise level workstation or server the 64 bit version is not necessary. Also, it is easier to find games and programs to run natively in a 32 bit OS so I personally prefer to use it as a desktop. As you may know, a 32 bit Ubuntu installation out of the box will only support 2.7GB of ram without PAE. This is a limitation of the 32 bit kernel but can easily be overcome by a recompile. In this tutorial I will walk you though the installation of needed packages, the obtaining of the kernel source, the recompiling and the packaging of the .deb files so you can install this easily should you need a reload or want to share the kernel with a friend. I found very few resources on the net for doing a recompile in Ubuntu and those I did find never mentioned PAE which is probably the most desired kernel option. Let’s get started!

Do I need PAE?

The fastest way to determine this is knowing what size ram you have installed in the system.Either login as root or sudo su and you can do the following:

# dmidecode | grep Size | grep MB
Maximum Memory Module Size: 4096 MB
Maximum Total Memory Size: 8192 MB
Installed Size: 2048 MB (Double-bank Connection)
Enabled Size: 2048 MB (Double-bank Connection)
Installed Size: 2048 MB (Double-bank Connection)
Enabled Size: 2048 MB (Double-bank Connection)
Size: 2048 MB
Size: 2048 MB

As you can see above we have 4096 MB of ram installed for a total of 4GB. Now let’s see what the OS reports:

# free -m
               total       used       free     shared    buffers     cached
Mem:           2771        704       2066          0         98        320
-/+ buffers/cache:        285       2485
Swap:         2045          0       2045

Based on the output above we can now see that the system can only see roughly 2.7GB of the 4GB installed.

Prerequisites

We will need some tools installed along with kernel sources so we can recompile. As sudo su or root issues the following commands:

# apt-get install linux-source-2.6.28 kernel-package libncurses5-dev fakeroot

Once these packages installed you will need to go to the source directory to extract the bzip file. A quick way of knowing where the source can be found is by issuing the below command:

# dpkg -L linux-source-2.6.28
/.
/usr
/usr/src
/usr/src/linux-source-2.6.28.tar.bz2
/usr/share
/usr/share/doc
/usr/share/doc/linux-source-2.6.28
/usr/share/doc/linux-source-2.6.28/copyright
/usr/share/doc/linux-source-2.6.28/changelog.Debian.gz

Based on this output we know the kernel source can be found in /usr/src. So lets cd to that directory:

# cd /usr/src/

Now we need to extract the contents of our kernel source with the following two commands:

# bunzip2 linux-source-2.6.28.tar.bz2
# tar xvf linux-source-2.6.28.tar

We now need to create a symlink in the src directory:

# ln -s linux-source-2.6.28 linux

The enter the symlinked directory:

# cd linux

Getting the recompile of the kernel going

To saves us some time from building a completely new config, let’s copy the old ( unless you want to build a new one) :

# cp /boot/config-`uname -r` /usr/src/linux/.config

Now let’s enable PAE support from make menu config:

# make menuconfig

Then scroll down and select –> load alternate config and load the .config and hit enter.

From this screen select –> Processor type and Features

Then –> High Memory Support (64GB)  – note: It will say support for 4gb is there bit it is a lie!

Select –> 64GB

Select –> Exit

Select –>Exit

Once these steps are complete, we will now start the recompile ( This can take some time, so grab a beer and watch T.V. or something):

# make-kpkg --initrd --append-to-version=-mykernel kernel_image kernel_headers

Note: the append-to-version=-mykernel can contain whatever you want so you can change this to say im1337 or whatever.

When the recompile finally finishes, cd to /usr/src and there will be two .debs for your kernel, install them as shown below:

# dpkg -i linux-headers-2.6.28.9-mykernel_2.6.28.9-mykernel-10.00.Custom_i386.deb
# dpkg -i linux-image-2.6.28.9-mykernel_2.6.28.9-mykernel-10.00.Custom_i386.deb

Reboot and you should now be good to go as the new kernel will default as #0 in the /boot/grub/menu.1st file. If anything goes wrong your old kernels will be there and you can boot back into them however any issues arising from this process is highly doubtful.

It seems with the latest unexplained seismic activity in the San Andreas fault (Fox New Story)  and the earthquakes that continue in Texas (Texas’s latest earthquakes ) one must wonder if the Earth is telling us something. I can’t ever remember a time where Earthquakes of any sizable magnitude were occurring in Texas! I recently wrote about a magnitude 3.3 earth quake that occurred not to far from Dallas on this post and they are still happening fairly often to date. For those of us interested in tracking these events you may find the following links helpful:

The USGS earthquake site :  http://earthquake.usgs.gov/index.php

Latest Earthquakes in the United States map :  http://earthquake.usgs.gov/eqcenter/recenteqsus/

Largest Earthquakes recorded in the United States: http://earthquake.usgs.gov/regional/states/10_largest_us.php

Google very recently announced the future release of Chrome OS. Is this a suprise? not really as there has been speculation for a long time that this would happen. Google has been running it’s own inhouse variant of Linux for quite sometime along with the Google Webserver platform. This OS will definitely be a Linux distro but how flexible they leave it remains to be seen. What is true is that Google is one of the only tech companies out there that can threaten Microsoft with a release like this. I think if they can seriously improve on Desktop Linux they certainly have a chance, but as of right now as much as I love Linux it is not my primary desktop choice. I feel it still is a bit beta feeling. Linux is the most powerful server platform in the world though so don’t think I am one of those MS folks.I am certainly excited about this prospect more than I am the Windows 7 relase ( I feel Windows 7 is just Vista rebranded) and will certainly give it a shot when it comes out. As soon as it does I’ll install it and give it a review! You can read more about this release on Google’s official blog: http://googleblog.blogspot.com/2009/07/introducing-google-chrome-os.html