Next Windows Server Gets Modular

It may not have a name yet, but Longhorn Server features were detailed Thursday at PDC 2005 and the watchword was "modular." Microsoft has broken down its server OS into components, and the system installs only the services required to fill a specific role.

At its core, Longhorn Server will contain no graphical user interface and boot directly to a command prompt. The Server Core simply contains networking, security and management services, along with Active Directory.

With just a 500MB footprint, the server can perform four roles: DNS, DHCP, Active Directory and static Web server for files. Even in this basic install, terminal services are supported, as is remote scripting.

A Microsoft spokesperson acknowledged the similarity to Linux and senior product manager Ward Ralston said the change was made in response to customer feedback.

"If users didn't ask for it, we wouldn't do it," he said, adding that Windows Server 2003 can operate in a headless mode, but the feature is not obvious to users.

A regular install adds on the graphical shell, MMC tools and the .NET Framework. But even with the full bits installed, Longhorn Server remains componentized and services are installed as needed. On first boot, a new Role Management Tool is the first thing users see, Ralston explained.

Roles are installed directly from the Longhorn Server DVD when activated and instantly patched using a feature called "secure-at-install." The idea is that going modular will keep the system locked down and reduce potential vulnerabilities caused by extraneous services running in the background.

Patches to Longhorn Server will also take advantage of new transactional capabilities added to NTFS that enable any file operation to be rolled back in case of an error. The feature, known as TxF, uses "very low overhead" and is "very, very efficient," said Microsoft senior vice president Bob Muglia.

Microsoft's new Web server, IIS 7.0, has also been redesigned around a modular architecture. Features have been broken down into individual modules that administrators can choose from when setting up Longhorn Server.

Ralston said that because Longhorn Server isn't due until 2007, it's not clear how Microsoft will package the modular components. However, the company is likely to retain its current SKUs for enterprise, Web and small business environments, which offer different sets of services to choose from.