Microsoft demos Longhorn 'hot swap' feature

Computerworld - Microsoft Corp. and NEC Corporation of America today demonstrated a feature of Longhorn that will allow administrators to add and swap processors, storage devices and memory without needing to take the entire machine offline.

In addition, Longhorn has now been officially dubbed "Windows Server 2008," even though it's still scheduled to ship in the second half of this year, said Eric Jewett, a Windows Server product manager at Microsoft.

Depending on the server manufacturer's implementation, a Longhorn-equipped server may also be able to spot hardware components that are about to fail and do a hot-swap on its own without human intervention, according to spokesmen from NEC and Microsoft.

The demonstration of Longhorn running on an NEC Express5800/1000 server running Intel Corp. Itanium 2 chips took place at this week's Windows Hardware Engineering Conference (WinHEC). NEC is the first hardware vendor to incorporate Longhorn's hot-swap feature, Jewett said, but other server vendors are working on it, too.

Jewett declined to name the other server vendors but said that Microsoft is partnering with suppliers to vertical markets including financial services, or for applications including databases or e-mail, where server availability is critical. Microsoft is making available an application programming interface (API) to allow server vendors to implement the hot-swap feature with their respective systems management software and firmware, Jewett said.

In NEC's case, customers are able to set policies that can, for instance, tell a Longhorn server to "borrow" processors and memory that may be sitting idle or were used for another application if a given application's performance threshold hits 90%.

The API is needed so the other system software and firmware to communicate with Windows Server 2008. In case of failure or when a preset threshold is crossed, the operating system can the entire system a "time out" so all jobs are in a state of suspended animation, according to the company. Then Windows moves all workloads to the new processors or memory and restarts the processing.

Longhorn is the first Windows server operating system to sport the hot-swap feature, which Microsoft calls dynamic partitioning. A broader definition of dynamic partitioning refers to the ability to segment server hardware into different zones, each with its own version of the operating system. Those zones can be expanded or collapsed, depending on the application's needs -- on the fly or at a predefined time. In this scenario, the computer can be reconfigured at 6 p.m., for example, to do database queries overnight and then reset itself at 8 a.m. to be ready to do high-transaction jobs during the day.

This type of dynamic partitioning has been available in mainframes and supercomputers for almost 40 years but is now also becoming part of less-expensive servers.