Stratus has included its own fault-tolerant drivers within the ESX Server hypervisor.

Although Stratus had worked with VMware on its GSX platform it said that it had taken time to develop drivers for the ESX platform as it was a “completely different product and different OS.”

"This approach is similar to the work that we have done with Red Hat and Microsoft in the past: we wanted to be sure that any installation of our joint technologies would be as simple as possible," said Andy Bailey, availability consultant at Stratus. "There is no additional effort required to make the VMware hypervisor continuously available when it is hosted on a Stratus server."

Running mission critical applications on virtualised servers is presenting the risk of a single point of failure says Stratus.

Where high availability systems handling a number of discrete applications have a server problem, with standard Intel technology those sessions have to restart, which means recovery time, assuming the data hasn’t been corrupted, the company said.

While VMware Infrastructure 3 includes a high availability module (VMware HA), there had previously been no way to protect individual transactions taking place within critical applications in a virtual machine.

"Deploying a fault-tolerant physical layer underneath the VMware hypervisor provides additional protection. For VMware, working with Stratus gives them the chance to increase the number of mission critical environments that are being deployed on virtual infrastructures," said Bailey.

The high availability capabilities within ESX mean that where failure happens “it is the HA side that will kick in, if you have a spare machine” users use Vmotion to move and restore those applications “but it will only work if you have two nodes that are working.”

Stratus said it will work to offer fault tolerant drivers for Microsoft Server hypervisor and Parallel’s Virtuozzo.