Tag Archives: computing

Top 500 Supercomputers: Linux and Others

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Linux seems to be a favorite OS for supercomputer makers.  There are distributions like SuSE, RedHat, and even CentOS in the mix.    You can browse the Top 500 website and see that about 89+ % of the OS family being used is Linux.

Some supercomputer vendors prefer to customize their own Linux distribution to adapt it to the unique architecture of their respective machines.  For example, for Cray Inc.’s XT6 and XT5 supercomputers, they use a Cray Linux Environment (CLE) that allows the OS to scale to hundreds of thousands of cores.

It’s good to hear that Linux is given the confidence in handling large amounts of data used in solving numerically big problems.  Good job, Linux!

OpenSUSE 11.2: A Test Installation

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A 4 GB 2.4GHz aluminum MacBook was used for this installation.  OpenSUSE was installed in a virtual machine created under VMware Fusion 3.  768 MB of RAM was allotted automatically by VMware Fusion.  When the image of the DVD of OpenSUSE was used, VMware correctly identified it as the 64-bit OpenSUSE distribution.

Virtual machine settings used for the test of OpenSUSE 11.2.

Virtual machine settings used for the test of OpenSUSE 11.2.

Two CPU cores were manually specified in the configuration since the MacBook is a dual-core machine anyway.  A measly 32 GB of disk space was allotted for the installation.  As for networking, it was decided that doing NAT behind the host was sufficient for this test.  Note that NAT was the default network mode used by VMware.

The install took about 30 to 45 minutes after selecting a number of packages beyond the default desktop packages.  In particular, a number of development tools like GCC and OpenJDK were installed.  Also, a couple more window managers were installed, including Metacity, IceWM, and TWM.  The GNOME Desktop Environment was also included.

Below is a screenshot of the initial boot-up screen:

Startup Options

OpenSUSE defaults to run level 5 for a desktop configuration. On VMware, the screen size is set to 800×600 pixels initially. Changing this involves editing the Xorg.conf in the /etc/X11 directory.  Note that an xorg.conf file does not exist here  yet.  One must be created.

The initial desktop presented to the user.

The initial desktop presented to the user.

To create a new xorg.conf file, switch to run level 3, which shuts down X. Then run the command ‘Xorg -configure’ as root. This creates a new xorg.conf.* file in root’s directory. Rename this xorg.conf and copy it to /etc/X11. Assuming it works, when you type ‘startx’ as a normal user,  a desktop session gets started.  When satisfied that it works, edit xorg.conf and add the line “Virtual xxx yyy” to adjust the resolution of the desktop and desktop manager (i.e. the login screen).  See the sample below:

Look for the Virtual keyword in this screen.

Look for the Virtual keyword in this screen.

After doing the above modifications to the xorg.conf file, the desktop looked like this on VMware Fusion, in 1680×960 pixel resolution:
Desktop at 1680x960 pixels.

Here are some sample screenshots of the window managers and desktop environments installed in this virtual machine:

Gnome Desktop Environment

Gnome Desktop Environment

Ice Window Manager

IceWM

And of course, X Window System’s venerable TWM:

TWM

TWM

That’s it for now. We’ll be adding more information about this test install in the next couple of days.