[MUSIC] Today, we're going to discuss the pros and cons of virtualization. We're going to really discuss cost versus footprint versus power versus a whole lot of things. Okay, let's talk about physical hardware for a few minutes. Let's talk about rack mount servers for example. Rack mount servers are about 19 inches wide and they can come in very small widthwise or what we call 1U, one unit. Or you could get up to six, ten very large servers, okay? Standard servers, probably around 2U, okay? It's about two inches high, three inches high, something like that, okay? About 19 inches wide and depending on what manufacturer it is, it could be maybe two to three feet long. It's a very, they're very long servers, because they have a lot of horsepower in them, all right? They also require a lot of power. So each one of those servers may require two power supplies at 1,100 watts. So we use two power supplies because of redundancy. What if one fails? The other picks us the slack, so they usually load balance the power across those two power supplies, okay? They can also be pretty expensive. Servers may be anywhere from $2,000 to tens of thousands of dollars. It just depends on what you put in the servers. What about space? Each one of the units may take up a lot of space. And you know exactly where they are. So, if we have a machine room like we do in the building that I'm currently recording in, they require a lot of space. They not only require space for physically being there, but we also need to cool them off. Electronics don't like heat, so they have to be cooled enough so they run efficiently. So virtualization, virtualization as we have talked about in previous lesson, virtual systems are designed to utilize resources. The servers, physical servers are generally, if you look at the industry as a whole, they are underutilized. We may only use 5 to 10% of the capacity of a physical server. With virtual systems, whether it's VMWare or QEMU, KBM, Hyper-V and others, we can make sure that our systems are utilized well. Okay, capital costs, capital costs are generally lower on virtualized systems because we may only have one or two chassis filled with blades. So the power supplies are a whole lot more. They may be 3 kilowatts each, but they're generally more efficient. So we may have four to six, in a nice chassis, we may have four to six, three-kilowatt power supplies. But historically, if we look at our servers, even the servers at this university. We've come up with each server, virtualize server, only uses nine watts of power on average. That's a huge difference from the 1,100-watt power supply in our physical RackNap Server. What about operating costs? Operating costs, again power, or cooling even. It's a lot less to cool versus many, many, many servers, okay? Data center expenditures as well. Space, if we don't have a lot of space, it makes sense to virtualize our systems. Efficiency is another reason why we virtualize. RAM memory, CPU usage, and storage are some of the reasons why we virtualize. Because we can utilize the maximum amount of the entire system instead of a small amount like we can in a physical system. Migration of workloads as well. What about outages? Outages have a detrimental effect on enterprise systems. So, we can migrate virtual workloads between servers. Cons, licensing. Licensing can be complicated. Server sprawl, we tend to not delete virtual systems. Whereas if they were physical, we may just depreciate them and throw them away or recycle them. Some hardware cannot actually be virtualized. Think of encryption. It's really hard to virtualize a TPM module for encryption. Admins may have access to everything. So that's another reason, that's another con that we may have. And thought must be put in to the system as well. We don't just put in one server, we put in many because what if one of those chassis fails. The chassis that's running all those virtual machines, well, you're not just taking one server down now, even in a physical server. You're taking down potentially hundreds of machines. So thought in bringing up virtual systems is a must. Okay, virtualization again takes thought and planning. Make sure all software and hardware can also be virtualized before you go down the virtualization route.