SLES 9 is the first enterprise Linux distribution weve tested that ships with the 2.6 version of the Linux kernelVersion 2.6.5, to be exact. Unlike SuSE Linux Professional 9.1, which was SuSEs first 2.6-based release and which shipped with a 2.4 kernel option, SLES 9 comes with 2.6 only. SuSE sites running applications not yet certified for 2.6 should stick with SLES 8 until theyve tested their applications on the new kernel.However, the 2.6 kernel is fast approaching its first anniversary and has had time to settle down, undergoing a series of bug-fixing revisions. In addition, hardware and software vendors have had time to adjust to the new kernelweve seen hardware and software support for 2.6 progress rapidly during the past several months.SuSEs YaST suite of configuration tools, long one of the distributions key differentiators, now includes several new modules, including a tool for configuring the new mail server that ships with SLES 9 and a client and server setup utility for the included IP Security VPN. We were particularly impressed with the changes in YaST for setting up Samba 3. The Windows-compatible file, print and authentication service can be confusing to configure, but in our tests, YaST did a good job of simplifying the configuration process. We could configure our test systems for basic file sharing as well as set them up to serve as primary or backup Domain Controllers in a Windows network. We were interested to see in YaST a tool for installing instances of User Mode Linuxa new feature in the 2.6 kernel that enables users to run virtual, contained instances of Linux as applications on their systems. User Mode Linux is well-suited for testing software or for isolating applications from one another and from the system for security reasons. As with handy open-source software components, User Mode Linux takes a bit of research and trial to configure properly, so we found this YaST tool a welcome additionalbeit one with room for improvement. We could use the YaST User Mode Linux tool to install an instance of SLES 9, but wed like to see this tool make it easy to install other Linux distributions as well. In addition, after the tool stepped us through the creation of an instance, it gave no indication of how to run that virtual machine. For that, we had to hit Google because the generally good SLES 9 documentation scarcely referred to User Mode Linux at all. Another snag we encountered was in setting up a network-based installation source for SLES 9, a step required for installing User Mode Linux instances. YaST contains a nice tool for copying the contents of SLES 9 disks to a system to be shared via NFS (Network File System), FTP or HTTP. The tool even let us publicize the presence of the installation source to other systems on our network via Service Location Protocol (at openslp.org). Unfortunately, the YaST tool for configuring installation sources for the system isnt set up to consume Service Location Protocol data; we had to run through a workaround provided in the SLES 9 release notes to get SuSE to accept the installation source wed set up. One hidden YaST improvement in this version of SLES is a change to the GPL (General Public License). YaSTs previous license restricted redistribution and kept YaST a SuSE-only component. With the license change, Novell hopes to see wider embrace of and more extensive development for YaST. The switch to less restrictive licensing has already begun to pay dividends, as trusted Linux vendor Immunix Inc. released a YaST module for configuring its application security product at LinuxWorld last month. Will a free YaST lead to an all-free, community-oriented SuSE release? Click here to read more. One thing we found puzzling in this release was the absence of certain desktop-oriented applications on the six disks on which SLES 9 ships. In particular, we missed the OpenOffice.org office suite and the GIMP image editing application. Although SLES 9 is a server operating system, and we can understand not including these packages in the default install, it doesnt make sense to exclude them entirely. Senior Analyst Jason Brooks can be reached at email@example.com. Check out eWEEK.coms Linux & Open Source Center at http://linux.eweek.com for the latest open-source news, reviews and analysis.