1 00:00:00,650 --> 00:00:04,050 When using virtualization, each emulated server runs 2 00:00:04,050 --> 00:00:07,210 its own operating system inside of a virtual machine, 3 00:00:07,210 --> 00:00:09,170 but the virtual machines are run on top 4 00:00:09,170 --> 00:00:11,540 of what's known as a hypervisor. 5 00:00:11,540 --> 00:00:13,730 A hypervisor may adjust the distribution 6 00:00:13,730 --> 00:00:16,070 of the physical resources of the server 7 00:00:16,070 --> 00:00:17,680 to the virtual machines. 8 00:00:17,680 --> 00:00:19,870 This includes the processor, the memory, 9 00:00:19,870 --> 00:00:21,983 and the hard disk space. 10 00:00:21,983 --> 00:00:24,610 Hypervisors come in two distinct flavors, 11 00:00:24,610 --> 00:00:26,570 Type 1 and Type 2. 12 00:00:26,570 --> 00:00:30,010 A Type 1 hypervisor is known as bare metal, or native, 13 00:00:30,010 --> 00:00:32,360 since it runs directly on the host hardware 14 00:00:32,360 --> 00:00:35,120 and functions as a type of operating system. 15 00:00:35,120 --> 00:00:40,120 Microsoft's Hyper-V, Citrix's XenServer, and VMWare's ESXi 16 00:00:40,240 --> 00:00:43,950 and vSphere are all considered Type 1 hypervisors. 17 00:00:43,950 --> 00:00:46,130 A Type 2 hypervisor runs from within 18 00:00:46,130 --> 00:00:47,630 a normal operating system, 19 00:00:47,630 --> 00:00:50,520 something like Windows, Mac, or Linux. 20 00:00:50,520 --> 00:00:52,320 For example, in the next lesson, 21 00:00:52,320 --> 00:00:54,960 I'm going to demonstrate how we can install Windows 10 22 00:00:54,960 --> 00:00:56,900 as an emulated desktop computer 23 00:00:56,900 --> 00:00:58,520 inside of a virtual machine 24 00:00:58,520 --> 00:01:00,680 that's being run by the software VirtualBox 25 00:01:00,680 --> 00:01:02,210 on my personal computer. 26 00:01:02,210 --> 00:01:05,100 Now, my personal computer is a Mac OS X desktop. 27 00:01:05,100 --> 00:01:05,950 But we're still going to be able 28 00:01:05,950 --> 00:01:07,710 to run Windows inside of it. 29 00:01:07,710 --> 00:01:10,050 That's the power of using something like VirtualBox, 30 00:01:10,050 --> 00:01:13,530 because VirtualBox is an example of a Type 2 hypervisor. 31 00:01:13,530 --> 00:01:17,200 Another good Type 2 hypervisor is known as VMware. 32 00:01:17,200 --> 00:01:20,150 A Type 1, or a bare metal, hypervisor is faster 33 00:01:20,150 --> 00:01:23,760 and more efficient than a Type 2, or hosted, hypervisor. 34 00:01:23,760 --> 00:01:26,410 This is because a bare metal hypervisor doesn't 35 00:01:26,410 --> 00:01:29,240 have to waste any of the physical computer's resources 36 00:01:29,240 --> 00:01:31,760 by running a full desktop operating system, 37 00:01:31,760 --> 00:01:34,070 like Windows or Mac, first. 38 00:01:34,070 --> 00:01:36,530 Instead, a Type 1 hypervisor acts as 39 00:01:36,530 --> 00:01:39,210 a stripped-down, specialized operating system 40 00:01:39,210 --> 00:01:40,860 to provide the physical resources 41 00:01:40,860 --> 00:01:43,300 to the virtual machines that it hosts. 42 00:01:43,300 --> 00:01:44,210 Now, I know I said there's 43 00:01:44,210 --> 00:01:45,830 only two types of hypervisors. 44 00:01:45,830 --> 00:01:48,050 But there is a third type of virtualization 45 00:01:48,050 --> 00:01:50,650 that's becoming popular in our networks today. 46 00:01:50,650 --> 00:01:54,470 This is called Application Container-Based Virtualization. 47 00:01:54,470 --> 00:01:56,140 With this type of virtualization, 48 00:01:56,140 --> 00:01:57,850 the operating system kernel is shared 49 00:01:57,850 --> 00:02:00,020 across multiple virtual machines, 50 00:02:00,020 --> 00:02:01,680 but the user space for each of these 51 00:02:01,680 --> 00:02:05,030 virtual machines is uniquely created and managed. 52 00:02:05,030 --> 00:02:07,710 Often called Application Containerization, 53 00:02:07,710 --> 00:02:10,340 this allows an organization to deploy and run 54 00:02:10,340 --> 00:02:12,690 distributed applications without launching 55 00:02:12,690 --> 00:02:15,090 a resource-heavy, full virtual machine 56 00:02:15,090 --> 00:02:17,030 with a full operating system. 57 00:02:17,030 --> 00:02:20,280 This makes Application Containerization much more efficient 58 00:02:20,280 --> 00:02:23,120 than either a Type 1 or a Type 2 hypervisor, 59 00:02:23,120 --> 00:02:24,760 if it can meet the needs of your business 60 00:02:24,760 --> 00:02:26,500 and your organization. 61 00:02:26,500 --> 00:02:28,640 Container Virtualization is commonly used 62 00:02:28,640 --> 00:02:30,630 with Linux servers, and some examples 63 00:02:30,630 --> 00:02:32,650 of Container-Based Virtualization software 64 00:02:32,650 --> 00:02:35,908 include things like Docker, Parallels Virtuozzo, 65 00:02:35,908 --> 00:02:37,793 and the OpenVZ project.