Marathon Technologies announced Monday that everRun VM, a product it says can provide high-level fault tolerance for virtual machines, will ship in April.

It represents a step up in capability from the Littleton, Massachusetts, vendor's previous releases, said John Humphreys, an analyst with IDC. "They were able to offer fault tolerance at the server level, now they've taken it to the virtual applications."

The application, now in beta, works by using at least two physical servers, each with either its own storage or based on a shared storage model. They are connected through what Marathon calls an "availability link," according to a demo presentation.

Users must first install Citrix XenServer Enterprise on each server to create guests. EverRun VM is installed on top of the hypervisor, below the guest layer. EverRun clones a guest to which users want to add availability protection and puts it on both servers. The two guests are then joined through everRun VM and seen as a single environment, the demo explains.

The product will offer varying levels of availability protection, from basic failover to system-level fault tolerance, which maintains application and memory state. That optional capability will be available in the fourth quarter, according to Marathon.

In the meantime, the software will provide "component-level" protection. For example, if a storage device fails, the input-output stream would be automatically redirected to the paired disk on the other host. Once a failed device is replaced, everRun will automatically resync it with its pair, the company said.

Administrators can view and adjust the everRun server environment through a Web-based management console, fine-tuning settings on each virtual machine.

Phillip Blucas, IT manager at Louisiana Public Broadcasting in Baton Rouge, Louisiana, said Monday he has been beta-testing the product for about a week.

"I see what it can do, and it's pretty cool. I'm not using it in production, that's for sure. But I don't see any reason why it wouldn't be good enough," Blucas said.

"It eliminates the need for a [storage area network], which is a big thing as far as I am concerned," he added.

Pricing for everRun starts at US$2,000 per server and $4,500 per server bundled with XenServer Enterprise.

Marathon's aggressive pricing strategy, which would help it sell to midmarket companies, makes sense for a couple of reasons, according to Laura DiDio, an analyst with Yankee Group. Smaller virtualization vendors like Marathon want to "move downstream" because there may be less bureaucracy around buying decisions at midsize companies, she suggested.