Fabric Design 101

So when your creating your SAN Fabric and your plugging in all your hosts , remember your storage array controllers also need , to be spaced across your switches.

Otherwise you could end up with a single point of failure in your fabric , if your ever decide to reboot a switch for any sort of maintenance. A fabric should be highly resilient , and allow you to reboot hosts ( dual pathing software installed of course & low I/O activity). If you can't then you seriously need to look at your fabric design.