Many an article has has been dedicated to subjects like scalability of services or enterprise capabilities of servers, but honestly, hardly a majority of people run their own data centers. However, a single server is all it takes to create a centralized infrastructure, and it doesn't need to offer a huge amount of computational power. What people do expect is more functionality. The server needs to act as a file, print, and intranet server; support groupware; implement a permissions concept; and provide access to simple cloud services and the like.

In small businesses that do not have their own IT department and do not employ system or network administrators in particular, you will often find staff without specific IT skills maintaining and managing the company's computer systems. For this target group, specifically, various software enterprises have developed server distributions derived from different Linux variants that promise fast setup and easy operation.

For this article, our team put six of these distributions to the test: ClearOS [1], Collax Business Server [2], Koozali SME Server [3], NethServer [4], Univention Corporate Server [5], and Zentyal Server [6]. The seventh contestant was a pre-installed NAS system by QNAP [7], which represents a class of modern office network-attached storage that offers services comparable to Linux server distros.

In our lab, it was all about installation routines and hardware support, which are typically the biggest obstacles that inexperienced administrators need to overcome. The test team also looked at how distributions behaved when setting up their services and whether or not they help newcomers avoid incorrect configurations. Last but not least, any server distribution worth its oats should have a mature maintenance concept that includes both manufacturer support and regular updates.

ClearOS

The first candidate is ClearOS [1] from the New Zealand-based ClearFoundation. This server system, formerly known as ClarkConnect, is based on Red Hat Enterprise Linux. The current 7.1 version is available in three variants. In addition to the free Community version, the vendor also offers Home and Business versions.

The two commercial versions are available by subscription for between $36 and $60 for ClearOS Home or between $110 and $590 annually for ClearOS Business Edition [8]. Vendor support is available for all three variants, varying from simple forum access and the online document, to an advanced Knowledge Base, to personal customer support.

Our lab team looked at version 7.1 on a 64-bit machine. The ISO image weighed in around 800MB. Users who still have legacy 32-bit hardware will find the slightly older version 6.6 on the website. ClearOS 7.1 supports filesystems such as XFS and Btrfs for the first time and acts as a virtual machine. The Business server has fairly moderate hardware requirements: 1GB of RAM and 10GB of disk space are all you need according to the vendor, which means that the system can be deployed on older hardware. With no Live version to try out, users need to install the distribution directly and are given support with an easy-to-use graphical wizard (Figure 1).

Figure 1: A graphical wizard is available for installing the ClearOS server.

The wizard prompts you for some localization information, then asks about the target disk, the network, and how you want to authenticate as the administrator. When you press Begin Installation the wizard loads the distribution onto your disk. After rebooting the computer, you can configure the ClearOS server in a web browser on the local network; you need to enter the HTTPS-protected IP address followed by port number 81 in the address bar. In the web interface, set the server's network mode. You have three choices: Private Server Mode (for a server used on your intranet without a firewall), Public Server Mode (for a publicly accessible computer with the firewall activated), and Gateway Mode , in which the ClearOS computer acts as a gateway for other clients. This variant assumes that the computer has two network cards.

Everything OK?

ClearOS performs a DNS lookup and then you need to register the server. After doing so, you are given access to updates from the manufacturer for your choice of subscription. The interface shows you a detailed list of packages, and you can click to update; you can also assign a server and domain name. The setup routine then opens the Marketplace , which lists additional modules (Figure 2). Clicking installs the goodies on your system.

Figure 2: Users can install additional services and apps from the ClearOS Marketplace at the push of a button.

The ClearOS distribution includes popular services with packages for operation as a DHCP, DNS, file, print, Samba, mail, and web servers. In contrast to other commercial products, there is also a free anti-phishing solution and intrusion detection and prevention software. Some security solutions, such as antispam filters and anti-malware packages are available, with several firewalls based on iptables. Be sure to take a close look at the description before installing a package.

One of ClearOS's unique selling points is the various media servers and a photo management tool, which means the server can be recommended as a multimedia center on your intranet. Thanks to the integration of Zarafa groupware and content management systems (CMSs), ClearOS also offers mature packages for commercial usage. Solutions such as OpenERP are available from additional repositories, as well.

User accounts and groups are easily set up using the dashboard; you need to go to the System | Accounts menu to do this. The system first expects you to define services, for which it then creates groups. As soon as groups exist, you can create accounts and assign them to one or multiple groups.

Maintenance

ClearOS automatically keeps the system up to date. For this to happen, you need to install the Software Updates app from the Marketplace, then set up the feature by selecting Configure , which means enabling or disabling automatic updates. If manual updates are enabled, you can manually trigger an update of all available packages by clicking on Update All ; however, you cannot select individual packages for updating. If you want to (re-)configure the update function at a later time, you can do so in the Cloud | Updates menu.

When it comes to maintaining the distribution, apps from the Marketplace can help you do so. They include blog viewers, bandwidth managers, backup and restore solutions, and synchronization services for syncing data between remote locations. Many of the packages are available free of charge, and the configuration wizard helps you set up the components.

Although popular services such as the firewall can be set up graphically in a short time – even by less experienced administrators – the support subscriptions offer several options in case of problems, ranging from simple telephone support through remote maintenance. Additional online documentation and forums round off the offering.