Review: SUSE Linux Enterprise Server 9


Author: Preston St. Pierre

SUSE Linux Enterprise Server 9 represents a significant step forward for GUI-based enterprise server operating systems. While others are still fiddling with the 2.4 kernel, Novell has jumped up to 2.6, adding several exclusive features that make SLES9 stand above its competition. On its surface SUSE Linux Enterprise Server 9 looks like a somewhat reduced version of SUSE Linux 9.1 Professional, but its most exciting features are hidden beneath the familiar green and blue GUI. Slackware or BSD servers are unlikely to be replaced by SUSE and its fancy interface, but Windows Server 2003 has no prayer against this production-quality server OS.

First let’s start with the basics: SUSE of any flavor is easy to install, maintain, and manage, and SLES9 is not a disappointment in that regard. The only trouble SLES9 has is in installing and activating the boot loader when a serial ATA controller is present (and unused) in the system. I never discovered a workaround for this, and the problem was verified by other sources with different machines. If installing to a SATA hard drive there was no problem and, ultimately, this is what I had to do to get the software working. I didn’t spend a lot of time tracking down the problem, but it occurs on other distributions of the same era, and it appears to be a problem with how GRUB guesses and assigns device names.

The installation procedure is as easy as it can be without skipping critical options. Likely you’ll be installing the server the first time from the CD media, but for emergencies or to install on other servers you can use the ZeroConf Service Location Protocol (SLP) to do the world’s simplest remote installation. The target machine automatically finds the installation server, reads its config files, and reinstalls the operating system all by itself. If nothing else, this offers the cheapest and easiest form of redundancy, allowing SUSE Linux Enterprise Server to replace critical yet aging UNIX systems.

ZeroConf SLP can also connect to about two dozen other services such as OpenSSH, NTP, CUPS, and LDAP, just to name a few. SLP is also compatible with Apple’s Rendezvous protocol.

The setup and configuration is as easy as it can get; the YaST management tool can usually detect your hardware and set it up for you, asking you about configuration options along the way. In the rare instance where your hardware is not recognized or supported, you usually have generic driver options that can get you going until you work around the problem or download the proper driver. That scenario is pretty rare; SLES9 has the most incredible hardware support of any commercial distro I’ve seen so far. It could even run some of the most advanced state-of-the-art hardware from Intel — a D915GUX motherboard with integrated PCI Express video and a uniquely modified Intel Pro 1000 LAN chip that even the in-development Fedora Core 3 could not use at the time I tested it. I had some trouble setting the video resolution at first, but it took very little work to get everything to operate properly.

Maintenance is, as always, handled by the YaST Online Update (YOU) utility. YOU can download and install updates automatically without any user intervention, or it can be scheduled to download updates only at certain times. The big difference between SLES9’s YOU utility and the one found in SUSE Linux 9.1 Professional is, Enterprise Server does not access public update servers by default. In order to receive updates from Novell’s update server, you have to have a “support key.” Novell said that they’d send me one of these so I could test out the service, but I never received it. I don’t like the idea of having to rely on a single vendor for support and update services, but fortunately Novell/SUSE has been reliable in the past.

YaST does a bit more than just change system settings: it controls network services such as DNS, Apache, NFS, LDAP, and many others. From YaST you can enable and disable these services as well as do most or all of your server configuration. You can, for instance, add or remove modules from Apache, set up the ZeroConf server, add network users and groups, etc. — all from a quick and easy-to-navigate GUI.

A minimal amount of desktop applications are also included: KDE 3.2.1 and GNOME 2.4.2 and their associated components are included in the full install, along with K3b for writing to optical drives and Mozilla for Web browsing and Web page authoring (the mail, address book, and chat components are not included).

Special features

With the exception of ZeroConf SLP and some unique portions of YaST, so far we’ve covered the features that are unique to SUSE in general; now we’ll outline some of the things new to SLES9 along with features that you won’t find in SUSE’s desktop distributions.

The 2.6.5 kernel that SUSE Linux Enterprise Server 9 uses is enabled for symmetrical multiprocessing (SMP) and employs four separate kernel I/O schedulers (CFQ, Deadline, Anticipatory, No-Op), which greatly improves performance for any disk-intensive applications. SUSE can also access the drive or array through multiple channels at once (multipath I/O), thereby allowing for better load balancing and fault tolerance. Class-based Kernel Resource Management (CKRM) in SLES9 allows the administrator to allocate resources at the user or job levels. This can stop DDoS attacks and increase the accuracy of programs that monitor resources. Lastly, SUSE-specific kernel enhancements allow up to 512 CPUs, 4 billion unique users, 65535 concurrent user-level processes, 4095 major device types and more than a million subdevices per type. The kernel also automatically tunes and adjusts its resource management to accommodate the maximum number of open files.

One of the most interesting new features in SUSE Linux Enterprise Server 9 is its integrated Usermode Linux (UML) capabilities. UML allows the kernel to create a virtual instance of itself as a regular process, enabling the administrator to create multiple virtual servers, all administrated through the same tools and programs as the “real” server. This can be useful for Web hosting providers, who could sell several virtual servers on one machine. You could also use the UML-created virtual instance to work as a firewall or for a Virtual Private Network (VPN). Using UML to create Linux virtual servers, you can also do some nifty load balancing tricks.

These are merely some of the highlights of SUSE Linux Enterprise Server 9’s extensive feature list. SLES9 is armed to the teeth with tools and applications that are easy to access, use, and understand; any but the most old-school, old-fashioned sysadmin will love SUSE Linux Enterprise Server 9.


I only tested the AMD64 and x86 editions. Novell says that the AMD64 edition, unlike many so-called 64-bit operating systems that have a 64-bit kernel and a 32-bit userland, is entirely optimized and compiled for the AMD64 architecture. According to previous benchmarking I’ve done with SUSE Linux Professional 9.1, that could yield performance gains of anywhere between 30% and 200% when doing memory and CPU-intensive operations such as encryption, encoding, and compiling.

SLES9 is available for IBM’s POWER architecture as well, but usually you’d buy it with the machine instead of separately from Novell.


In the future I’d like to see Novell do some better testing with a wider variety of x86 and AMD64 hardware. The SATA problem would have been a serious problem if I hadn’t had a SATA drive to use for the review.

Other than that one glitch, SUSE Linux Enterprise Server 9 is easily the most powerful, comprehensive server OS on the market. It spans three major architectures, offers tools to do pretty much anything that can possibly be done with a networked server, and it’s easy to use and install. To top it all off, it’s cheap — U.S. $389 for the 2-CPU edition, and there are no restrictions in licensing. Compare that to Microsoft Windows Server 2003 Standard Edition, which is nearly three times as much and you must pay per-seat licensing for client machines. Even among GNU/Linux distributions, there is no competition for this product as it is out of the box. Sure, you can hack any GNU/Linux distro to do what SLES9 does — sysadmins have been doing it for years. SUSE Linux Enterprise Server 9 reduces the hassle and wasted time that is generally associated with installing, configuring, and then using a server.

Purpose Operating system
Manufacturer Novell
Architectures x86, AMD64, POWER
License The core distribution is under the GNU GPL, but some ancillary programs included with the distribution are under proprietary licenses
Market Enterprise corporations
Price (retail) U.S. $389 for the 2-CPU license, $939 for the 16-CPU license
Previous version SUSE Linux Enterprise Server 8
Product Web site Click here

Jem Matzan is the author of three books, a freelance journalist and the editor-in-chief of The Jem Report.