Fedora 18 as a server distribution

Test Lab

Article from ADMIN 14/2013

By Thomas Drilling

Fedora is a trend-setting distribution that sets the pace for future developments of Red Hat Enterprise Linux. Administrators, regardless of whether they use Fedora, are well advised to look at the newest innovations of the Fedora distribution.

The latest Fedora release had to wait more than two months before it was officially released to compete for users' favor. That Fedora 18 proved to be "extremely buggy" or "completely useless" according to the assessments after the first tests hardly helped improve the situation. However, this criticism relates primarily to desktop use, and in particular to errors in the new Gnome version 3.6.2 and the massively revised Anaconda installer. Under the surface lies a whole series of innovations of interest to ambitious users and administrators.

A Choice of Desktops

From the perspective of admins and developers, Fedora 18 provides interesting prospects, particularly with regard to its use as a server or virtualization and cloud management platform. The rightly criticized deficits for desktop use (the Anaconda installer and Gnome) are less relevant for admins because, on the one hand, Fedora 18 provides enough stable alternatives with KDE SC 4.92, Cinnamon 1.6.7, Xfce 4.10, and MATE, and on the other hand, most server admins can probably do without a graphical interface completely.

Moreover, Fedora 18 is available not only in the standard version as an installable Live CD with the Gnome desktop, but also, as used for this test, in a directly installable DVD variation and in the form of spins for KDE and Xfce. Alternatively, just like KDE and Xfce, the Gnome 3 fork Cinnamon and the Gnome 2 fork MATE can simply be installed from a standard Fedora system with Gnome 3.6.2.

Taming Anaconda

In spite of all the installer's deficiencies, any admin should be able to install Fedora 18 in the desired manner (partitioning) with the new installer, even though available updates cannot be installed during the installation. These features from the old Anaconda could not be integrated in Fedora 18 because of time constraints, but they should be back in Fedora 19.

Criticism of the visually revised Anaconda is primarily directed toward manual partitioning of the hard disk space. Thanks to smart default settings and automatic partitioning, it more quickly provides a usable system with minimum user interaction. The installer already begins copying files in the background while the user is still configuring missing or optional settings, such as the time zone, the locale, or the root password.

For manual partitioning, you click on Installation destination on the Anaconda main installation menu and then select the desired device in the list marked Local Standard Disks . Optionally, the Full disk summary and options link delivers more information about the highlighted device. A click on Continue first leads to the Installation Options , and, in my test, Anaconda pointed out there that there was enough free space on the freshly created virtual SCSI disk for automatic partitioning.

If you want to partition manually, you must first unfold the Partition scheme configuration line and then select the partition type: Standard Partition , LVM , or Btrfs . Using an inconspicuous checkbox, you can also encrypt the partition.

Current criticism of the partitioning module also refers to usability, which is more cumbersome than in the old Anaconda version, at least from the user perspective. More serious, however, are some bugs in the new Anaconda. For example, the program crashed reproducibly during a test when Btrfs was the selected partitioning scheme, because the disk was apparently too small. The limit, according to the Fedora wiki, is 8GB. In the second attempt, the installation with a larger Btrfs partition executed properly, and Btrfs proved to be as stable in operation (Figure 1). The new System Storage Manager (SSM) tool for disk management had no problems dealing with Btrfs.

Figure 1: Fedora 18 supports the new Btrfs filesystem in the boot partition – as long as it is at least 8GB.

After installation, the bootloader and kernel, which are digitally signed for the first time, ensure that Linux will boot, even on machines secured by UEFI Secure Boot (see the box "Boot Blockade").

Boot Blockade

On computers that are certified for Windows 8, operating systems must be signed with a key from Microsoft if UEFI Secure Boot is enabled. This requirement poses a problem for the Linux world, because Linux will no longer simply boot on such hardware. In Fedora 18 [14], the solution is a bootloader with certificates signed by Microsoft. However, Fedora goes a step further than the approach introduced by Canonical with Ubuntu 12.10, in which only the bootloaders, but not the kernel, are signed.

Compared with Canonical's approach, which only ensures that Ubuntu will start on Windows 8 PCs, Fedora's approach also protects against malware that activates itself before the operating system is booted, which according to Microsoft is the primary purpose behind secure boot. The Fedora 18 bootloader signed by Microsoft loads only a Linux kernel signed by Fedora and the subsequent signed modules. Thus, the complete Fedora boot chain is protected.

However, the method holds serious disadvantages, particularly for desktop users, because with Fedora 18, it is impossible to load proprietary graphics drivers from NVidia or ATI when Secure Boot is enabled. If desktop users want to install proprietary graphics drivers anyway, they must disable secure boot in the UEFI firmware. Another alternative would be to equip the kernel with self-generated signatures and designate it as trusted in the setup. More details on the topic of UEFI Secure Boot and Fedora can be found at the Fedora website [15] and Fedora kernel developer Josh Boyer's blog [16].

DNF Package Manager

Fedora 18 includes DNF [1], a new package management tool that is based on the code of Yum 3.4 and is intended to replace Yum fully in one of the next Fedora versions. Like openSUSE, DNF now uses the libsolv library [2] for more reliable resolution of dependencies (Figure 2).

Figure 2: Fedora 18 includes DNF, a new Debian packaging utility.

Furthermore, in Fedora 18, DNF and Yum are based on RPM version 4.10, which is supposed to be more stable and faster than its predecessor. Additionally, many RPM packages now contain information [3] to help the user or a debugger more quickly determine which part of the code harbors the problem. Although the full set of debugging information is still included in the debuginfo packages, the packages are smaller, thanks to improved DWARF compression [4].

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