Debian on AMD64

These days, just about every major distribution (with the notable exception of Slackware) is offering an AMD64 port of their principal product. This is mainly in anticipation of increased popularity of the 64-bit processors in the future and to gain experience in solving challenges that exist while developing a distribution that would be not only considerably faster than its x86 counterpart, but also equally usable - both on servers and workstations. In the upcoming series we will look at how different distributions (Linux and BSDs) handle these challenges. We will try to answer a question that some readers contemplating a new computer system might be asking: is the AMD64 processor ready to satisfy our most demanding computing tasks?

We will start with Debian GNU/Linux, which has always been the most multi-platform Linux distribution on the market. Woody, the current stable release for over 2 years, and Sarge, the new upcoming stable release due out in a month or two, support no fewer than 11 architectures. Perhaps surprisingly, AMD64 is not one of them and it won't be in Sarge either. That said, Debian developers have been working on an AMD64 for some time, and unofficial builds, including Sarge installation CDs and documentation, are already available on the Debian AMD64 Port pages. There are two unstable (=sid) branches - "pure64" and "gcc-3.4". The former is compiled with GCC 3.3 and is considered more stable, while the latter is compiled with gcc-3.4 which is said to have a better support for AMD64, but is less well-tested. An AMD64 testing branch is also available with a plan to build a full unofficial Sarge release at a later stage, but it will not enter the main Debian Sarge branch and it is not yet clear how security updates will be handled for this product.

Despite the unofficial status of the port, those who wish to run a fully-enabled 64-bit Debian distribution on an AMD64 processor can do so today. We installed it on a system with the following specifications: AMD64 3500+ processor (2.2GHz), K8N Neo2 (Socket939) mainboard from Micro-Star International, 1 GB of DDR SDRAM, 2 x 120 GB Maxtor hard disks, Plextor PX-712A DVD/CD Rewritable Drive, and NVIDIA GeForce4 Ti 4600 graphics card. If you are curious about the cost, the processor + mainboard + memory came to about $620, but anything newer than the 3500+ processor would cost dramatically more; for example the current prices for the AMD64 4000+ processor start at $715 (without the motherboard and RAM).

To initiate the installation, we downloaded the most recent Debian "netboot" ISO image (4.4 MB). This is a bootable CD that attempts to auto-configure networking before it proceeds with downloading and installing the base system. The installation was rather painless and the only non-standard place was the selection of FTP/HTTP mirrors; as was mentioned earlier, the AMD64 branch has not been included in the Debian's main branch and is maintained separately on the Alioth server. Therefore your preferred download server and selected AMD64 branch have to be entered manually. Besides the main server, a handful of mirrors in Europe and Asia are also available. As soon as the installation completed and the bootloader was configured, we were prompted to reboot into our brand new Debian AMD64 system. We continued with installation of packages for a typical workstation - a full graphical desktop with GNOME 2.8 and KDE 3.3.1, as well as most other general applications. The entire experience was rather dull (in a positive sense of the word) and everything we threw on the apt-get command installed without any problems at all. Perhaps we shouldn't have been surprised - the Debian AMD64 Ports page claims that 97% of all Debian packages compile just fine for the AMD64 processor which is, in fact, the second most complete port, after i386.

Although we were impressed by the quality of the port and the trouble-free system installation and configuration, there was little doubt that sooner or later we would run into some AMD64-specific issues. Firstly, there was the remaining 3% of applications that have yet to be ported to AMD64, with OpenOffice.org being the most glaring of the missing pieces. Secondly, what about the many useful binary-only applications, such as Acrobat Reader, Macromedia Flash Player, the NVIDIA graphics driver, Opera, RealPlayer, etc., most of which are built for i386 only (the NVIDIA graphics driver is the only notable exception)? There are two ways to solve the problem. The first one is by installing a set of IA32 libraries which should allow users to run most i386 applications, while the second one (a more proper way, since some would argue that mixing IA32 and AMD64 libraries is not the right way of maintaining a clean system) requires an installation of a basic 32-bit system into a chrooted environment.

The second option is slightly more involved, but this HOWTO explains the procedure in simple terms. After installing the "dchroot" package, configuring it and creating a simple shell script for launching the chrooted 32-bit applications transparently from within the 64-bit environment, we were able to install and run OpenOffice.org, Acrobat Reader, Opera and RealPlayer with no problems. Thus, we ended up with a Debian system that was almost complete and very close to what we would have on an x86 workstation. There were still some missing pieces - for example, it is not possible to get a 64-bit browser to load the 32-bit Macromedia Flash plugin, so the only way to view Flash-enabled web sites was from within the chrooted 32-bit Opera (or any other chrooted 32-bit browser, if installed). Of course, this method of running certain applications is still a lot more cumbersome, than it should be, but it will do for the time being. Eventually the Debian developers will port OpenOffice.org to the AMD64 platform and, if we scream loudly enough, we might even get the makers of the above-mentioned proprietary software start building AMD64 ports of their applications. In the meantime, it is not too difficult to run a full 64-bit system with a handful of "forbidden" 32-bit applications in a chroot jail.

Before installing Debian on the AMD64 system, we had some worries about the ability to maintain an efficient working environment on this relatively new platform, fearing compatibility issues, maybe even instability. Luckily, this turned out not to be the case. Although still labeled as beta, Debian's AMD64 port has so far proved to be a trouble-free, high-quality distribution that is certainly ready for deployment on high-end developer workstations. The system is incredibly responsive, it boots twice as fast as a the 1.4 GHz P4 box sitting next to it, and overall it has been an enormous pleasure to use it. AMD64 is a great processor and Debian developers have built a excellent product to take full advantage of its power. This experience has removed whatever doubts we had about the present state of quality 64-bit computing.

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