Red Hat – Enterprise Linux 5 review

server and workstation OS with built-in virtualisation
Photo of Red Hat – Enterprise Linux 5
€62 upwards (desktop subscriptions), €287 upwards (servers), €1,235 upwards (Advanced Platform), all per syste

Red Hat would like you to believe it significant that its latest enterprise platform – Red Hat Enterprise Linux 5 (RHEL 5) – was released on Albert Einstein’s birthday. That isn’t significant, but it is a notable event in the company’s history and RHEL 5 is a welcome update to a product last refreshed almost two years ago to the day.

As with all new Linux distributions, RHEL 5 sees the adoption of the latest kernel technology (2.6.18) along with numerous updates and enhancements to the other open source components included in the package. Of far greater significance, however, is the inclusion of integrated virtualisation facilities designed, for the first time, to be deployed in a production environment; about which, more shortly.

In the meantime, the other big change is in the way the product is packaged, the aim being to simplify licensing, although it’s arguable whether that has actually been achieved.

A subscription model still applies here, where you pay an annual fee for updates and support for the open source software, and are limited in what you can do by the licence involved. However, gone are the old, tiered ES and AS server subscriptions which have been replaced by a single RHEL 5 server with support for all available processors including 32-bit and 64-bit industry standard chips, multi-core and SMP implementations.

Nothing is left out. It’s the same server package regardless of what subscription you take out, with a full complement of virtualisation features included based on the XenSource hypervisor technology. To this end you get support for both so-called para-virtualisation – limited to running modified implementations of RHEL 4 and 5 – and full virtualisation where other guests, including Windows, can be run unmodified. However, full virtualisation is only possible when the host server is equipped with the latest Intel and AMD processors where the necessary virtualisation technology (Intel VT and AMD-V) is built-in.

Unfortunately, just as with the old ES product, buyers of the base RHEL 5 server are still limited to hosts with two processor sockets and, with the new release, just four virtual machines. To get more than that you have to take out a subscription to the Red Hat Advanced Platform which has no limits when it comes to either processor sockets or VM instances.

Moreover, as well as RHEL 5, the Advanced Platform includes the Red Hat Cluster Suite and Global File system products to virtualise storage as well as servers. All of which makes it a lot easier to migrate and move virtual machines about for load balancing and failover purposes.

Pricing also stays the same. As such, ES customers can upgrade to the base RHEL 5 product immediately, as can AS users who will be able to get the other Advanced Platform features when they renew their subscriptions.

The old desktop implementations have also been combined – sort of – with the previously separate Red Hat Desktop and WS (Workstation) subscriptions replaced by a single RHEL Desktop in this release. However, just to complicate this otherwise radical move, two new enhancement options have then been added, one of which (the Workstation option) effectively re-creates the old WS product. The other is a new Multi-OS option adding virtualisation support, not normally included in the base Desktop. Up to four virtual guests can be supported when this option is applied.

We tried out both server and desktop and found them very easy to install. We particularly liked the option of keying in an installation number, supplied with the subscription, to automate the process and configure the setup to match the licence purchased. Minimal operator input is then required and you can install any implementation from the same media.

Performance is also much enhanced in this release, especially on multi-core platforms, although in our tests the Red Hat solution didn’t prove significantly faster than other enterprise Linux implementations on the same hardware.

Most of the other enhancements are tucked away under the hood and not immediately noticeable. These include enhanced support for IPv6 and better integration with Active Directory when running Samba. Desktop users also get support for high performance graphics cards, but the Gnome desktop remains more or less unaltered apart from a new RHEL 5 wallpaper. Plus there’s the same frustrating lack of integrated management tools like those provided by Novell in its SLES 10 product.

Still, it’s a welcome update to the market-leading Red Hat platform and the virtualisation features alone make it well worth the wait.

Company: Red Hat

Contact: 0800 358 2018

Along with the usual round of open source updates, Red Hat Enterprise Linux 5 also sees the introduction of integrated virtualisation facilities designed, for the first time, to be employed on production systems. Licensing has also been revamped, with a single desktop package, a unified server and an Advanced Platform implementation which adds useful clustering and storage virtualisation facilities.