Debian 6 Offers Updated Applications, Few Rough Spots

Version 6 of Debian GNU/Linux, the popular open-source project that bills itself as “the universal operating system,” hit the Internet on Superbowl Sunday, packing a trove of updated applications and a pair of new editions to burnish its universal billing.

The distribution, which already stands out for its broad processor architecture support—spanning 12 architectures—branches out in version 6 with 32- and 64-bit editions based on the FreeBSD kernel. These new editions, while rough around the edges, open new opportunity for technology sharing among separate open-source operating systems and indicate that the project that gave birth to Ubuntu Linux continues to drive open source in new directions.

This latest release, which is also known by the Toy Story-inspired name “Squeeze,” will play well in server deployments that draw on open-source components, which the Debian project has a knack for packaging up for easy installation over one of the project's repository mirror sites.

Debian 6.0 can also work well in a desktop role, particularly for users who wish to closely control the versions and configuration of the software on their machines. Debian is known, in its stable branch, for lagging behind the cutting edge in the versions of the software it ships, but once you become familiar with the distribution, it’s possible to mix in applications from the project’s testing, unstable and experimental branches to tune one’s environment.

GNU/kFreeBSD

The Debian 6 feature that I was most interested in checking out was the operating system’s new 32- and 64-bit FreeBSD kernel variants, both of which carry a “technology preview” label. While most Linux-based operating systems are simply called “Linux,” the Linux open-source project only produces the kernel of these operating systems—the code wrapped around the kernel is the product of many different projects, the most central of which is the GNU project, which produces the C library and the constellation of applications (known as “userland”) that makes Linux into a Unix-style operating system.

GNU/Linux and most Unix-style operating systems, including those distributed under an open-source license, tend to be licensed incompatibly with each other, which has kept nifty, open-source software advances, such as Sun’s DTrace instrumentation framework and ZFS storage system, from making their way into Linux-based operating systems, even as these features have spread into more compatibly licensed Unixes, such as FreeBSD.

Debian’s kFreeBSD flavor works around these licensing issues by marrying the GNU C library and userland with the kernel from FreeBSD 8. As a result, this version of Debian inherits the kernel features and hardware support of FreeBSD, while maintaining compatibility with most of the Debian software package catalog.

By sticking to the GNU C library, the kFreeBSB branch avoids many of the issues that troubled an earlier Debian project to port the NetBSD kernel to Debian along with the BSD C library. However, this key library difference carries its own complexity—for instance, DTrace is practically unusable in kFreeBSD for now due to missing userland components. For a Debian-style distribution with better feature compatibility with Solaris (albeit with fewer available packages) check out Nexenta at nexenta.org.

When I spun up my first Debian kFreeBSD virtual instance, I noticed that FreeBSD lacks the enhanced “virtio” drivers that boost I/O performance with Linux or Windows operating systems running under KVM—a difference that was noticeable in the time it took my Linux and FreeBSD-based instances to install.

Given my interest in kFreeBSD’s potential for bringing previously inaccessible features into Debian, I was pleased to find ZFS as a partition option in the Debian installer application. However, over the course of several installations, I was unable to create an instance with a working ZFS partition from the installer—it appeared that the system wasn’t installing the needed packages to get ZFS working. I was, however, able to create ZFS volumes once I’d finished installing and booting into a standard install with UFS-formatted partitions.

Installation and Updates

I tested the amd64 version of Debian GNU/Linux 6.0 on a dual-core Dell notebook with 3GB of RAM, as well as on a handful of VMs (virtual machines) hosted under the KVM hypervisor on that test notebook. I created VMs for the 64- and 32-bit versions of the distribution in both its GNU/Linux and GNU/kFreeBSD configurations.

For most of my installs, I opted for Debian’s network-based install media—relatively small (around 140MB) disc images that reach over the network to Debian mirror servers to fetch the files needed for an installation. One of the benefits of this install route is that the system grabs all the pending updates during the install process, so there aren’t dozens of packages to fetch after first boot.

Debian 6 is also available in a LiveCD version, similar to what other Linux distributions offer, which enables users first to try out the operating system before installing it on their hard drives.

Unlike most other Linux distributions, installing Debian 6 comes with the additional wrinkle, depending on one’s hardware, of separately installing any device firmware that fails to meet Debian’s free licensing requirements. With version 6, the Debian project has managed to excise all non-free firmware from its default install sources—a long-time goal of the project.

My test machine required such a firmware file to drive its Intel 4965AGN wireless network adapter. The Debian installer prompted me to provide the needed file, which I attempted to do using a USB stick, but the installer couldn’t detect the the firmware. I tried with FAT and ext3-formatted USB media, but to no avail. I forged ahead with my wired NIC, which did not require additional firmware, and fetched the missing firmware from Debian’s optional non-free repository after installation.

Once my system was up and running, I was pleased to note that some of the software management tools I’m accustomed to using in Ubuntu (which is a Debian derivative) have made it back upstream. In particular, Ubuntu’s App Store-like  Software Center, and its easy-to-use Update Manager tools, are available in Debian 6, both of which put a friendly face on the distribution’s massive collection of ready-to-install software packages.