Monday, February 3, 2014

Virtual Switches and Dinosaur Teeth

"Dude, that's a shark's tooth."
You can make some educated guesses about the life of a dinosaur just by examining a single fossilized tooth. You can guess its size, whether it was carnivorous, and whether it was a predator or a scavenger. Sure, you can be wrong, but it's an educated guess based on trace amounts of evidence.

It's this idea that I keep in mind when I'm getting to know a new vSphere implementation. I don't need access to vCenter, or to see vCOps data to get a good idea of what's going on. I just need to ask one question: "What kind of virtual switches do you use?"

The answer tells me a lot about the maturity and complexity of the infrastructure, and even informs me about the skill level of the technical staff who manage the environment. Here's what I think about the answers:

"We only use vSS"

Primitive deployment of vSphere. Perhaps it's the original deployment from many years ago, just maintained and upgraded in place without any notion of redesign or modernization. Most likely, if a shop is using pure vSS, there's little to no automation in place. Hosts and VMs are configured by hand. I'll make the leap and assume that people are asleep at the vWheel here, and aren't aware of advances in the vSphere product, or in the capabilities of the dvSwitches on the market.

"We use vDS"

Interesting. vDS indicates that someone who knows a thing or two about vSphere Networking spent some time with this design. That, or someone got lucky while messing around on a quiet Friday afternoon. And since vDS opens up so many more networking features (especially in these last two releases of vSphere), I assume that there's some semi-exotic magic in play here. But I also assume that, since a vDS can greatly simplify your host networking configuration in an HA cluster, there just might be some automation involved. Maybe host profiles, maybe Auto Deploy.

"We use vSS and vDS"

Either you're insane or brilliant. TBD.

"We use the 1000v"

Ugh. This tells me that your workplace suffers from organizational problems that technology alone cannot solve. Or maybe you needed the functionality that only the 1000v provided. But as the vDS matures, the 1000v loses a lot of its exclusivity claims, and the complexity begins to outweigh the benefits. (Don't get me wrong; I tried to love the 1000v for a long time. I just find it hard to justify these days.)

Now before you jump all over me for making gross assumptions and oversimplifications and judgmental statements about Cisco's dvSwitch, let me say this: when you look at a single data point, you can't describe a line with any degree of certainty. But just like dinosaur teeth can tell you about dinosaurs, virtual switches can give you a glimpse into the maturity of a vSphere environment.