Setting out to be all things to all people is generally a bad idea, since you're likely to end up leaving everybody at least a bit disappointed. However, Novell's SUSE Linux Enterprise Server 11's readiness to serve a broad range of hardware and application masters is arguably more virtue than vice.
After all, OS platforms are expected to bring together an organization's equipment and code to shoulder a diverse assortment of workloads. And, judged by the breadth of the roles it attempts to take on, SLES 11 meets those expectations. For example, while the platform continues to serve its traditional role as host for Linux and open-source applications, Novell has included SLES 11 support for Microsoft .NET applications, as well.
Along similar lines, SLES remains focused on delivering virtualization hosting through its bundled Xen hypervisor, and on providing enhanced application isolation through Novell's AppArmor functionality, but the platform also now includes experimental support for archrival Red Hat's KVM hypervisor and SELinux security framework.
However, all of SLES 11's people-pleasing doesn't come without a cost. When taken individually, and compared with more narrowly focused rivals, certain SLES 11 roles tend to disappoint. In particular, given the time that's elapsed since I reviewed the virtualization capabilities of 2006's SLES 10, I had expected that SLES 11 would have drawn closer to the streamlined deployment experience of VMware's ESX Server or Citrix's XenServer.
More promising are the steps that Novell has been taking toward making SLES a better guest for virtualization. These include offering an installation option for the product that results in a slimmed-down server instance that does away with unnecessary hardware drivers and includes a kernel that takes advantage of VMware's VMI (Virtual Machine Interface).
Also, Novell has partnered with rPath to create SUSE-based virtual appliances, in addition to Novell's in-house efforts around the appliance-building OpenSUSE Studio project.
Somewhat counter-balancing the feature-set ambitions of SLES 11 are the modular support options that Novell has built into the product. SLES 11's Mono hosting capabilities are sold as a separate extension at a cost of $200 per server. Similarly broken-out extensions are available for adding high-availability support and real-time performance capabilities to the platform.
The SLES 11 Mono extension contains a newer version of the open-source implementation of Microsoft's .NET Framework than what ships by default in SLES (Version 2.4 versus 2.0.1). The extension is intended for hosting .NET server workloads and may be upgraded independently from the rest of SLES as new Mono versions become available. (For more on running .NET applications with Mono, see Jeff Cogswell's analysis.)
Also on the topic of support, Novell has integrated into the system's software management toolset information about the support level that customers can expect for the various components that ship with SLES 11. For example, the packages for experimentally offered SELinux and KVM functionality are marked as "unsupported," while a package I installed from SLES sister distribution OpenSUSE was marked with a support level of "unknown."
Along similar lines, SLES 11 includes a tool, called suse-sam (Supportability Analysis Module) that I could use to scan my system and determine whether it was in a supportable state. This sort of utility will grow more important as Novell and other Linux vendors work to squeeze their distributions into new shapes--such as virtual appliances--while preserving their application and hardware certifications.