The Small Business Server Replacement is Clear(OS)

When it comes to the Internet, Linux is a big win.

Mail and web servers, databases, computational clusters and supercomputers all belong to the domain of free software. When it comes to embedded devices, Linux is also king of the roost.

There are two main areas where Linux has still not broken through, however – the desktop and servers for small business. Many small to medium enterprises are already “Microsoft shops” because the desktops run Windows. To break in, Linux needs to slot into these environments without causing a fuss.

Certainly the cloud is offering one solution to this problem, but not all companies are willing to put their sensitive data on-line and in the hands of another. So, a market for local servers to perform these functions is still alive and well.

The requirements

Part of the reason that Microsoft Small Business Server (SBS) is attractive is that it includes many core features required by a company, out of the box. Important services like central authentication, email, file and print sharing and web. Perhaps most important of all is calendaring. It’s something which businesses simply cannot survive without and has been a thorn in the side of Linux based alternatives for a long time.

Here’s a quick glance at some of the main features included with SBS:

Centralized Authentication (Active Directory)
Mail, calendaring and instant messaging (Exchange)
Webserver (IIS)
Firewall (ISA)
Content management system (Sharepoint)
Antivirus (Forefront)
Database (MS-SQL Premium version only)
Remote Desktop Services
Virtual Private Network (VPN)

Putting company culture and licensing issues aside, if Linux is to compete with SBS it needs to at least perform these specific functions. Not only that, but any Linux operating system needs to be a drop in replacement. It needs to work seamlessly and be simple to use.

It’s one thing to replace a back-end server with Linux, but the desktops aren’t going to go quite so easily. The Linux server therefore must also act as a Primary Domain Controller (PDC) for the Windows based network. This will enable Windows machines to join the network and make use of features such as roaming profiles.

Secondly, if it looks and works differently, users will complain. Most of these companies will be using Microsoft Outlook as the front end to mail and calendaring. Ideally, any Linux server should also work with Outlook.

The answer becomes clear

Why hasn’t Linux broken into this market, like it has with other larger server infrastructure? It’s not because the tools to handle these functions do not exist. On the contrary, in each of these individual areas Linux excels. That’s right. Linux can act as a Windows PDC, share files, serve printers, let alone webservers and databases!

Previously the biggest chink in the armor was decent support for calendar and contact sharing. These days however, there are dozens of options in the form of various groupware implementations. Yes, this too is no longer a hindrance, which is good because it’s a major reason why SBS is still used so heavily.

So all the required various tools exist and any experienced Linux user should have no trouble building a powerful SBS replacement. That’s good and well, but when sysadmins are not Linux savvy they require an operating system that installs these features out of the box, with an easy to use interface. If Linux is too hard to use, they will continue to use Windows. Not only does there need to be a major incentive to switch from Windows to Linux, there need to be as few stumbling blocks along the way as possible.

Now, meet ClearOS, a free and open source Linux distribution which does just that. ClearFoundation released the stable version of ClearOS 5.1 just before Christmas and it is available for download.

It might sound like a new kid on the block, but actually ClearOS has a long history going back to the turn of the century. It was previously known as ClarkConnect, a very popular distribution for setting up a Linux server quickly and conveniently. ClearOS is now built on CentOS, which is in turn built from the source code of Red Hat Enterprise Linux. As such, ClearOS has a solid and reliable foundation.

Features galore

ClearOS pulls all those required features together in a small, simple to install and use package. It can turn any machine into a sophisticated, reliable and powerful server for any network.

So what does it offer? Here’s just a taste:

Centralized Authentication (LDAP)
Primary Domain Controller (Samba)
File and Print Services (Samba and CUPS)
Mail (SMTP, POP, IMAP, Webmail)
Calendaring (Kolab groupware)
Webserver (Apache)
Firewall plus intrusion protection (iptables, Snort)
Antimalware (Clam Antivirus, Antiphishing, Antispyware)
Antispam (Spamassassin)
Database (MySQL)
Virtual Private Network (IPSec, OpenVPN, PPTP)
Web Proxy (Squid)

The complexity of these individual components is hidden behind the web based management interface, where users can simply turn on and off these modules as required.

While users are encouraged to administer the system via the provided management interface, it is also designed to be extensible. The back end is not hidden away, but offered up in plain sight for admins to get right in and change things if they want to. Various how-tos provide details on how to perform extra functions, such as enabling shell access for users.

ClearOS supports external modules, that is extra services outside of those included by default. This is part of the design goal of the operating system which will hopefully foster collaboration and increase its range of useful features. It is possible to replace the default groupware server with a more sophisticated one or even create new custom modules, such is the flexibility.

The included Kolab groupware server is reasonable, however it appears that a connector for Outlook must be purchased separately, such as that from Toltec or KONSEC. A feature rich, but rather unattractive, web client is also included via Horde. Linux users can have native support through KDE’s Kontact application, or Mozilla’s Thunderbird and the Sync Kolab addon.

The installer is straight forward and supports both hardware and software RAID. During installation the user is able to select a number of services to include, however these can also be configured at a later stage via the web management interface.

The web-based management interface is very intuitive and easy to follow. Server features are broken up into sections, such as Directory, Network, System and Gateway, where admins can configure various components thereof. Everything, from adding a user to configuring an IPSec VPN is a matter of a few simple steps. Within 5 minutes an administrator can have a fully functional Windows domain server, with all the bells and whistles. Pretty neat, eh?

Also built into the interface are various reports, such as the state of system resources, traffic usage and analysis, mail and web server statistics, as well as good old system logs.

ClearOS Web Management Interface

It would be good to see some improvements in the interface, to provide greater feedback. While installing packages for example, the interface appears to be doing nothing, while it is in fact downloading or installing. Reading the install log makes sense, but only if you know what you’re looking for. It would be great to see a simple feedback method in addition to the log. A rotating orange swirl while performing the task would suffice, turning green upon completion. It’s also a shame that there is no 64 bit version, however this might come at a later date if warranted.

Despite this, ClearOS is truly a decent replacement for Windows SBS. It has all the features yet is simple to manage and has the full power of Linux and free software right behind it.

Support options

Of course, another major component of any computer network is commercial support, which ClearFoundation also provides via their ClearCenter.

At the heart of this is the Clear Service Delivery Network, or ClearSDN. Registration to ClearSDN is free and in fact required in order to obtain the software updates it provides to keep your installation up-to-date and secure.

ClearSDN also offers various paid services, including:

“Software [antimalware] updates, content subscriptions, new features modules, technical support and cloud-based applications such as remote server backup.”

While the ClearOS software itself is open source, there are a few caveats. System updates are provided free of charge, however definition updates for the antimalware components are not.

ClearFoundation will also soon launch their own hardware appliance, called ClearBOX. This device will be pre-configured with ClearOS, certified and tested. So while anyone can download the software and install it on a server, those looking for an even more complete package should be able to find it soon enough.

ClearCenter also encompasses commercial support via ClearCare:

“ClearCARE is the innovative method that customers use to obtain technical support for ClearOS, ClearSDN and ClearBOX. Services are provided using a credit system with flexible purchase and payment terms.”

Finally, ClearFoundation has created a Web 2.0 community portal for everything related to ClearOS. It’s a single place where ClearOS users can get support and interact with each other via a friendly interface.

When it comes to ClearOS, you are not left out on your own. High quality commercial support is available to ensure servers run smoothly, which is something important to business.

Roll out the red carpet

Overall, this product is truly excellent. It serves the purpose of a drop in, easy to use Windows Small Business Server replacement and performs all required functions well. It has all of the services required of a server for a small to medium business network, plus several more to boot. The installation is simple and the interface reasonably intuitive enough that non-Linux admins can look like pros.

Hopefully over time it will grow and develop into an even more robust platform with some higher enterprise functions, such as clustering. It would be great to be able to expand an install over multiple machines with replication. It will be exciting to see where this operating system will go. Hopefully with a little more success and notoriety it can become a serious contender in the worldwide market. In the mean time however, it’s here and it’s ready to serve.