"A converged fabric architecture takes a single type of fabric (e.g. Ethernet) and converges various protocols on it in a shared fashion. For example, Cisco’s UCS converges IP and Fiber Channel (FC) packets on the same Ethernet fabric. Egenera’s fabric does the same thing on both Ethernet fabrics (with our Dell PAN System solution) and on an ATM fabric (on our BladeFrame solution)...
"Dynamic Fabrics are not converged, but rather separate fabrics that can be have their configuration modified dynamically. This is the approach that HP uses. Rather than utilize a converged fabric, HP has separate fabrics for FC and Ethernet. These fabrics can be dynamically re-configured to account for server fail-over and migration. HP’s VirtualConnect and Flex10 products are separate switches for Fiber Channel and Ethernet traffic, respectively."
"The 3rd type of fabric is a Managed Fabric. In this architecture there is no convergence at all. Rather, the vendor programs the Ethernet and Fiber Channel switches to allow servers to migrate. This is a bit like the Dynamic Fabric above, however, these typically are not captive switches and there is no convergence whatsoever."
I'll take some liberty here, and emphasize a pretty important point:
Converged /managed fabrics aren't attractive just because they simplify networking. It's because they are a perfectly complementary technology to managing server repurposing as well. That's for *both* physical servers and virtual hosts.
It's no wonder why IBM (with their Open Fabric Manager), HP (with their Matrix bundle), Cisco (with UCS) and Dell/Egenera (with the Dell PAN System) are all pushing in this area.
Why? Because once you have control over networking, I/O and storage connectivity, you've greatly simplified the problem of repurposing any given CPU. That means scaling-out is easier, failing-over is easier, and even recovering entire environmentns is easier. You don't have to worry about re-creating IPs, MACs, WWNs etc., because it's taken care of.
So, if you can combine Fabric control with SLA management and then with server (physical and virtual) provisioning, you've got an elegant, flexible compute environment.