The I/O Director takes the traffic flowing off all the servers' VMs through the virtual I/O devices and sends it out to its proper physical device, whether a network router or Fibre Channel storage switch. I/O Director serves as a variable mix of virtual network interface cards and host bus adapters to move the converged traffic away from the server and into the network fabric.
Xsigo customers typically use two cables so that one may serve as an alternative channel in case of a device failure, said Jon Toor, VP of marketing at the six-year-old firm. Xsigo was one of the first high-speed appliances that hit the market to relieve the emerging I/O bottleneck of servers running multiple VMs and becoming overloaded with network and storage traffic. The I/O Director is a 2u or 4u rack-mount device that virtualizes I/O by bringing converged traffic off the physical server and routing it through virtual network interface cards or virtual host bus adapters.
A virtual network interface looks like a physical device to the VM on a host server. It achieves a connection between VM and network that meets the requirements for isolation set by the Payment Card Industry standard for credit card financial transactions. But because the I/O has been virtualized inside I/O Director, levels of I/O bandwidth can be assigned and reassigned dynamically through its XMS management interface.
The two Infiniband cables serve as the equivalent of 64 cables between network interface cards or host bus adapters to specific devices on the network, Toor said. When it comes to 40 Gbps speeds for I/O, "we don't see any users who can consume it fully," said Toor, in an interview. The I/O Director was previously limited to 20 Gbps speeds, but Xsigo wants to stay ahead of the trend to load more VMs on one server and provide headroom for expansion, he said. One I/O Director can handle the traffic from many virtualized hosts, he added.