High performance Linux distributions Super and Underground Desktop

Built for Speed

By Marcel Hilzinger

BMW AG

The beauty of Linux is that you can shape it to do whatever you want it to do. Several distros focus on high performance. Of course, there are always many paths to any solution, and all the high performance Linux distributions take a slightly different approach to delivering better performance. This article examines a pair of promising but relatively unknown Linux distributions built for speed.

Super Linux is a Suse-based distro designed to serve as a testbed for new openSuse technologies. Super is essentially a faster and more bleeding-edge version of openSuse. The Super developers provide higher performance by embracing technologies that are considered too risky or too new for a mainstream enterprise product such as openSuse.

Underground Desktop Linux takes a different path to achieving high performance. Unlike many derivative distros, which are based on the code of mainstream titans like Debian, Suse, and Red Hat, Underground Desktop comes from the high performing and minimalist Arch Linux distribution. Arch is specifically optimized to deliver high performance on the i686 architecture, and Underground Desktop delivers the optimizations of Arch to a friendlier desktop Linux environment.

We'll show you what we found when we took these high performing distros for a test drive.

Installing Super Linux

Super [1] and Slick [2] started life as separate projects. Both are based on Suse Linux, and both aim to add features that Suse does not officially support. As there was a lot of overlap between the two projects, the developers recently decided to focus their energy on a single project.

If you are interested in replacing your Suse Linux with Super Linux, you can download one of the three ISO images from [3]. super-open-SUSE-final- 20051003- standard-minimal.iso comprises the basic system without a GUI. The super-openSUSE-final-20051003-standard-kde.iso and super-open-SUSE- final-20051003-standard-gnome.iso images are feature-rich CD images with the KDE or Gnome desktop. Check the "Accelerating Suse" box for more information on converting an installed Suse Linux version to Super-Suse. The Super installation is not much different from a standard Suse installation.

We notice two things in our lab:

• Super opens port 22 for remote SSH access by default.

• Super disables automatic login via the K Display Manager by default.

When you reboot, Super sets up the Prelinker, which helps programs launch more quickly. To do so, the Prelinker modifies all your binaries and libraries. Depending on your CPU, this process can take up to 45 minutes. When finished, you can log in to KDE or Gnome with your normal user name.

rpm http://ftp4.gwdg.de/pub/linux/suse/apt SuSE/10.0-i386 rpmkeys base java update extra suser-jengelh suser-guru suser-jogley suser-agirardet packman packman-i686 wine suse-people security

apt-get update
apt-get install kernel
apt-get dist-upgrade

Underground

The Underground Desktop [4] install is text-based. Underground Desktop was formerly based on Debian and had a graphical installer. The developer decided to move to Arch Linux. Version 020 is now based on Arch Linux "Noodle" and, just like Super Linux, it adds performance-tweaked CK patches to the kernel [5]. Underground Desktop uses Reiser4 for the root directory and the RC1 version of KDE 3.5.

After booting from the CD, a welcome screen appears listing the individual steps (Figure 1). Click OK and select the disk where you will be installing Underground Desktop. Click the entry showing the size of the disk, and create a swap partition, and a root partition, as a minimum requirement. Choose type 82 for the swap partition, and type 83 for the root partition. When you are done, quit the menu, and then press DONE>> to continue. In our lab, Underground Desktop could not handle existing partitions and displayed the following error:

/bin/setup: 473: Syntax error:5245191 32098/1000000

After we deleted two partitions and rebooted, the cfdisk tool performed as expected. If you prefer to format an existing partition, select DONE>>.

Figure 1: The text-based Underground Desktop installer just needs two partitions and the root password.

Use the next two dialogs to specify the root partition and the swap area for Underground Desktop. You can either select the partition you just created or choose to format an existing partition. Set the root password in the next dialog. Underground Desktop now displays an overview screen (Figure 2) for the installation. The whole procedure takes less than ten minutes. You can then log on as root in the new KDE desktop. Underground Desktop did not detect our lab machine's hardware correctly. The screen resolution was set to 1024x768 instead of the optimum 1280x1024, and it was impossible to enable 3D acceleration support for the ATI card.

Figure 2: Before launching into the install, Underground Desktop displays an overview of critical parameters.

Finishing Touches

Underground Desktop and Super both displayed the graphical KDE login screen after the install. The Super desktop looked neat and tidy and stuck to the Suse defaults. Underground Desktop puts numerous icons on your desktop, some of which can help you configure the system, but also including four games.

We tested Internet access first. Super gave us DHCP-based Internet access at first asking. Underground Desktop set up a static IP address. But you can click the Lan Setup icon on the desktop to switch to DHCP. There are also ADSL and modem connection icons on the Underground desktop. Underground does not support ISDN. Sound and printing worked out-of-the-box.

The GUI-based Underground Desktop package manager, Guzuta (Figure 3), comes pre-configured. After launching the program and clicking on Refresh, you can install packages from the full range of Arch repositories: Community, Current, Extra and Testing. pacman adds command-line package management support.

Figure 3: Underground Desktop's GUI-based package manager, Guzuta.

Super involves more effort. Start by adding the required Apt repositories to /etc/apt/sources.list. See the "Accelerating Suse" box. Super does not have a GUI-based package manager for Apt. You can give the following command:

apt-get installkynaptic

to install the Kynaptic package manager. Following this, even newcomers should have no trouble installing packages.

Pros and Cons

Super and Underground Desktop are designed to be high-performance desktop distributions, although version 020 of Underground is obviously intended as a test version. However, we were a bit disappointed with the Underground's enormous performance problems. DVD and video playback was jerky. Other programs did not launch as fast as we would have liked, and froze on occasions.

Some research on our part exposed Reiser4 as the culprit. Reiser4 puts the machine into a split-second freeze while synchronizing the filesystem. The KDE tools ksysguard diagram in Figure 4 gives you a clear view of what is going on. A workaround that does not actually remove the issue, but at least gives you reasonable performance, is to stipulate the noatime,nodiratime mount options for the root directory in /etc/fstab. Interestingly, the problem did not affect all of our lab machines, and we are still working on discovering the cause.

Figure 4: The KDE system monitor graphic showing regular CPU peaks in Underground Desktop.

Underground Desktop has a good selection of programs: Mplayer and Xine are both on board, and Libdvdcss is preinstalled. System notifications are configured, and Underground played audio files out-of-the-box. Underground Desktop performed well in our stress test, which involved burning a CD, compiling a program, and playing MP3s at the same time.

Admittedly, we did find the choice of programs for the basic system slightly strange, as it lacked common packages such as openssh for remote access, or hdparm for hard-disk tuning. We were surprised that the distribution used the Lilo bootloader. Grub is far superior, especially on machines with multiple distributions.

We assume that the Underground developers chose Lilo on account of Reiser4. Underground Desktop's boot time is fast - 35 seconds - but the system failed to live up to the expectations we had for Reiser4. It remains to be seen if the Reiser4 bug has been eradicated by the time version 021 is released, and if so, the next version will definitely be worth looking into.

There were no performance issues with Super/Slick. Using Ext3 as its root filesystem, Super set a new boot record of just 29 seconds. Super wasn't fazed in the least by our stress test, which involved burning a CD, compiling a program, and playing a DVD at the same time. The only niggle we had with Super was that the distribution is too similar to Suse Linux to be really cool. On a more positive note, the developers are working on a new version with a modified KDE. The new version should be available for downloading by the time this issue hits the newsstand.