Today's multi-core servers can drive a lot of bandwidth, particularly when running a large number of virtual machines or executing I/O intensive tasks such as VMotion or backups. Some virtual I/O solutions limit bandwidth to only 10Gb per link, which is less than half the capacity of many servers. The top virtual I/O solutions deliver bandwidth up to 40Gb/s per link, thus exceeding the capacity of the server itself. This ensures that the I/O link never becomes a bottleneck in performance.
4) Future proof
A key benefit of the private cloud is the ability to run any application on any machine. But this requires that all servers have access to a common set of I/O resources. What happens when something changes, such as an upgrade to 10G Ethernet or 8G Fibre Channel? Do you then upgrade all servers? Or do you minimize cost and disruption by only upgrading a portion of them? If you chose the latter, you've now limited the flexibility of your cloud; you no longer have the same I/O on all servers. Look for a virtual I/O solution that will let you propagate new capabilities out to all servers without having to modify the server or its cabling. That will maintain the integrity of your cloud down the road while saving you time and money.
5) Open standards-based
When shopping around, select a virtual I/O solution that is built on open standards and proven interoperable across systems from all leading vendors. This way, you can reuse your existing hardware and achieve infrastructure convergence without being forced to standardize on one vendor. This will reap big dividends down the road when it's time for your next equipment purchase and you have the flexibility to shop among multiple vendors.
As we move to the next level of virtualization -- to the private cloud model -- we are finally fulfilling the true promise of virtualization. The result is dramatically higher efficiency, thanks to 10x better equipment utilization and phenomenally increased compute density. Best of all, the user experience improves while costs come down, the ultimate win-win.