Virtualization continues to make huge inroads, thanks to the obvious flexibility and reliability benefits. And getting the most out of virtualization almost always requires some kind of shared storage. Otherwise, features such as live virtual machine migration and automated virtualization host failure recovery simply aren't available.
In many businesses, particularly large and medium-sized ones, most shared-storage implementations end up being IP storage -- sometimes NFS, but generally iSCSI. IP-based storage is an excellent fit because it employs the same networking hardware and concepts that network admins are already familiar with. And it's easy to get up and running.
But just because it's easy to fire up doesn't mean it's easy to do it right. Though less expensive than Fibre Channel, IP-based storage can actually be more complicated to configure optimally than FC storage. It's not as simple as punching in a few IP addresses. Constructing a reliable, high-performance network to support an IP storage infrastructure requires careful attention to a variety of different factors.