Red Hat, Suse refresh OSes

It wasn’t that long ago that Linux made for a decent server and a geek’s workstation. Now, Linux makes for an enterprise-class server and could be my mother’s workstation — it already runs on her TiVo.

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With the recent release of Novell’s SLES9 (Suse Linux Enterprise Server 9) and the even more recent release of RHEL4 (Red Hat Enterprise Linux 4), there’s much ado about something in the Linux OS space.

Suse’s Assimilation

Of the two OSes, Suse Linux has the hardest road ahead. The Novell acquisition has lit a fire under the development team, but it’s likely to be a year or more before we see a truly cohesive product that melds the old-school Novell paradigm to the new Suse foundation.

That said, Suse isn’t losing any ground. SLES9 is a solid and capable Linux distribution with all the power and scope that you could hope for, but it occasionally tries too hard in some places and not hard enough in others.

The installer has the polished, all-graphical feel that marks most Linux distributions these days. On a few lab servers, however, the installer couldn’t accurately detect the video hardware initially, and called the text-based installer as a fallback.

The normal Suse installer configuration, preparation, and package selection modules of the YaST (Yet Another Setup Tool)-driven install are present, with a few minor changes to incorporate newer features such as the LDAP directory server configuration panels.

SLES9’s default options are relatively well-thought-out, with the possible exception of the DES default on local password encryption. It may be the Unix standard, but times have changed (MD5 and Blowfish are provided as options).

The OS boots to Linux kernel v2.6.5, with Suse customizations. Device detection wasn’t an issue on any of the server-class hardware in the lab, including a wide array of common SATA and SCSI RAID controllers. Some less expensive controllers will prove problematic owing to a lack of hardware vendor support.

Suse includes some handy options in the initial install, including support for encrypted volumes, which isn’t present in Red Hat. Truthfully, these are configured as crypto loop devices, not actual encrypted partitions, but the capability is there. The LDAP configuration is also straightforward, as is the default authentication method.

Suse Linux has always been big on management, and SLES9 is no exception. The YaST2 toolset is a great benefit, providing simple GUI configuration and management of most major functions of the OS.

When you step outside those boundaries, however, things become complex in a hurry. If a particular package has an option that isn’t supported by YaST2 and SuSEconfig, then manual modification of the SuSEconfig scripts may be necessary. That can result in somewhat erratic behavior during updates and, if the admin isn’t careful, can cause configuration files to be rewritten without the previous changes.

For instance, to add a milter definition to a sendmail configuration, you must modify the sendmail SuSEconfig script to include the INPUT_MAIL_FILTER definition in the sendmail macro file, because SuSEconfig builds the macro file during its run rather than relying on a flat file. Once you overcome those hurdles, the packages function as they should — but if you’re planning on coloring outside the lines often, be prepared for some legwork.

Suse’s update framework is built on YOU (YaST2 Online Updater), a tool that links to a Suse site to retrieve and install security patches and system updates. Although not as streamlined as Red Hat’s up2date, YOU now provides a reasonable array of features, including automatic updates.

Red Hat Rolls On

Red Hat released RHEL3 in October 2003 and took some heat for not incorporating the new v2.6 kernel via update when it was officially released in January 2004. RHEL4 marks Red Hat’s official foray into the new kernel, with RHEL booting to a customized v2.6.9 kernel.

RHEL4 may look familiar to everyday Linux users because Red Hat has been investing heavily in its community-supported spin-off, Fedora, Red Hat’s original Red Hat Linux line. RHEL4 was developed from a Fedora Core 3 release candidate version.