NEC cranks fault-tolerant servers with Xeon six-shooters

Fault-tolerant servers can be carved up using hypervisors, but once again, NEC and Stratus do a lot of additional testing so they can maintain the availability levels for which they are charging a substantial premium. Prior Express5800 FT servers supported VMware's ESX Server 3.5 hypervisor, which Mitsch said NEC did without making a lot of fuss, and in the wake of VMware's vSphere 4.0 announcement in the summer of 2009, the company eventually put support for ESX Server 4.0 out for its Express5800 FT machines. Mitsch says that NEC is testing support for ESX Server 4.1 right now and will get it out the door as soon as possible on the three machines in its current lineup.

The Express5800 fault tolerant machines now also support Microsoft Hyper-V R2 hypervisor, which is a requirement NEC is getting from many customers who want to have tight clustering for virtualized Exchange Server groupware and SQL Server databases alongside their applications. Up until now, companies were buying multiple FT setups from NEC and networking them together, but not a lot of customers will be able to virtualize and put all of the applications on a single two-node cluster.

Windows Server 2003, Windows Server 2008, and Windows Server 2008 R2 are supported as operating systems on the NEC FT machines, whether virtualized or running on the bare metal, and so is Red Hat's Enterprise Linux 5.5 operating system. However, formal support for the KVM hypervisor is not yet available, even though it is embedded in RHEL 5.5.

"We are looking at KVM," says Mitsch. "We have the technology to enable it, so it is not a matter of if, but of when. But we don't have customer demand for it yet."

What NEC and Stratus alike have is a strong partner in Microsoft, which does not have software-based fault tolerant features encoded in its hypervisor, as VMware does in the fault tolerance feature in the vSphere 4.1 stack. With VMware's FT feature, the company is providing lockstepping over the network between two server nodes and making use of its VMware HA cluster feature.

The problem with the VMware FT is that it is limited to scaling to one virtual core. NEC's hardware-based fault tolerance can scale a virtual machine image to the size limits of the current hypervisors, which is four cores for Hyper-V and eight cores for ESX Server.

Maybe VMware needs to buy a hardware vendor?

NEC is taking orders for the Express5800/R320b-M4 server starting today, and the machine will start shipping some time in November. The machine comes standard as a rack-mounted cluster, but there is a tower adapter kit if you want to roll it into an office environment, as many NEC customers do. ®