SUSE Linux Enterprise Server: A server-optimized version of the vendor's Linux distribution
If the explosion of interest in Linux in the late '90s represented a revolution of sorts, the past few years have been a cooling period during during which the multitude of available distributions slowly shrunk to a small crowd. Of that crowd, one of the two most prominent is SUSE, which survived a brutal post-boom winnowing with smart partnerships and a product that earned notice from big-iron outfits like IBM and a just-completed acquisition from Novell, not to mention a loyal low-end customer base which values the company's fussy attention to detail.
SUSE Linux Enterprise Server 8 (SLES) is a server-optimized version of the vendor's Linux distribution. It represents a continuation of the company's tradition of producing solid product, with the added value being a level of consistency and portability up and down the enterprise food chain -- it provides the same APIs and basic layout running on anything from a humble commodity server to an IBM mainframe. This consistency is provided in large part by the United Linux effort, a consortium designed to establish a standard Linux platform (and compete with U.S. Linux front-runner Red Hat).
SLES ships in a plastic binder that provides a 339-page manual and four CDs. SUSE has long been known for providing quality documentation, and SLES is no exception. The manual is broken into installation and administration sections. The installation section offers clear and useful advice on topics such as remote installation (SLES offers a VNC-based installation option to allow for installs on headless machines) and simple topics, such as hard drive partitioning.
The installation itself can be handled in an automated fashion reminiscent of the default Windows approach, as well as in a hands-on fashion with numerous options to fine-tune the installation in terms of hard drive partitioning and package selection. We did a run-through of each method and found that while the more automated installation did a fine job of covering almost every contingency, it took a kitchen sink approach to package selection. There's an option to override its choices, but this approach does relative newcomers to Linux no favors: For example, we're inclined to believe there's seldom a need for more than one desktop environment on a server.
The less automated installation path gave us near-total flexibility, and that's the approach we recommend for instances where the machine has a predetermined purpose. It results in a more streamlined, economic installation with fewer moving parts and less potential for extraneously running services and the security liabilities they incur.
The installation software is heavily supplemented by the manual as well. Although Linux veterans will likely find almost every choice familiar (regardless of previous distribution they may have used), and less-experienced administrators will probably receive all the help they need from hints provided by the installer, Linux novices will find the manual a useful prop while navigating an installation the first few times.
SUSE provides a great deal of software in SLES, most of which should be familiar stuff to most Linux distributions -- Apache, Samba, and CUPS printer software.
Another installation option is the automated "Kickstart," developed largely at rival Red Hat (and available courtesy of its open source license), which allows for a one-time configuration to be recorded and reused across multiple installations.
One feature that's long distinguished SUSE across its product line is its emphasis on "YaST", or Yet Another Setup Tool, its general-purpose configuration and installation software. While other Linux distributions struggled with substandard configuration tools, SUSE took it upon itself to create its own software, and pointedly excluded it from unrestricted distribution under a liberal open source license.
YaST2 is in use in SLES, and it provides a useful window into the inner workings of the distribution as well as some good tools for routine system maintenance. Some highlights that caught our attention were the following:
- YaST Online Update, which provides a one-stop location for installing patches over the Internet, from vendor CDs, or from update CDs SUSE itself distributes.
- An option to edit the /etc/sysconfig file, which provides a central configuration file for much of the SUSE's core functionality. We were pleased to see that YaST orders much of this information in a more human-readable form than the file itself and offers sane alternatives to settings in drop-down menus. It also provides a GUI answer to self-documenting configuration files.
- Options to perform periodic backups of the RPM package management database. Although the RPM is generally solid, corruption does occasionally claim the file it uses to record the status of the thousands of packages that make up a given distribution. SUSE is wise to include a simple way to automate maintenance of this key file.
- Access to a collection of "powertweak" settings (i.e., parameters that can be set "by hand" by such arcane methods as flipping a bit in the guts of the /proc filesystem, but prove much more accessible and easier to find when provided in menu form).
- A straightforward firewall configuration tool.
YaST2 also provides access to user and group configurations, video settings, printer setup, basic configuration of network filesystem (NFS) shares, basic mail transport settings, and several other options essential to maintaining a basic server setup.
As good as YaST2 is, however, it does not provide access to everything, and that's where SUSE's excellent documentation steps in again, addressing several things YaST2 doesn't, including how to set up AppleTalk (a fading concern as OS X propagates through the Macintosh world) and Samba shares (the key to using almost any Linux file server in a Windows-dominated environment).
SUSE has also made Linux Logical Volume Management (LVM) much easier than it once was. It is now simpler to add disk space to a given server.
As a nod to database applications, SLES provides raw device support to enhance database performance.
SUSE also provides support for four journaling file systems common to Linux distributions: ReiserFS (which SUSE has supported for some time), ext3 (which provides backward compatibility with older default Linux filesystems), xfs (contributed to Linux by SGI), and jfs (contributed by IBM).
SUSE lasted as long as it did, and probably attracted new parent Novell's attention, because of its remarkable attention to detail. SLES is no exception to this tradition, providing a solid installer and good configuration and management tools. Much of the value here is not so much in the software itself (YaST excepted), which is common across most Linux distributions, and more around the way that SUSE has packaged it all up and integrated it smoothly.
The company provides a list of "utilization scenarios" under which it proposes SLES would be effective, and we're inclined to agree that it does make a formidable option in most of those cases, although the traditional value proposition of Linux on commodity servers will be diluted if it is pressed into service for some of the simpler scenarios, especially file and print sharing in less-sensitive areas.
Pros: Great documentation; Excellent configuration software;
Good support for higher-end features; Good self-documenting setup
process (when a more-hands-on approach is taken); More portable up and
down the enterprise architecture due to adherence with the United Linux/Linux
Cons: Default installation is a bit bulky for a server, making for more post-installation tweaking; May be overkill (and overexpensive) for simpler operations
Reviewed by: Michael Hall
Original Review Date: 1/14/2004
Original Review Version: 8