Virtual Machine Summary – Systems Engineering & Integration

Virtualization is using software to emulate one or more physical components in a computer system. Be familiar with the following types of virtualization:

Server virtualization allows multiple instances of server operating systems on a single physical computer. With server virtualization, you can migrate servers from older hardware to newer computers or add virtual servers to computers with extra/unused hardware resources.
- The physical machine is called the host operating system.
- The virtual machine is called the guest operating system. A virtual machine is also referred to as a VM.
Network virtualization allows multiple virtual servers to communicate using networking protocols as if they were attached to a physical network.
Storage virtualization partitions physical storage on one system for use by multiple virtual servers. You can also use virtual storage to create or imitate storage devices such as iSCSI storage units.

The Hyper-V role in Windows Server 2012 enables you to create and manage virtual machines. Be aware of the following Hyper-V details:

Hyper-V can be installed on a full installation of Windows Server 2012 or a Server Core installation.
When you add the Hyper-V role using Server manager, the hypervisor software and the hypervisor management tools are installed.
It is best practice to install only the Hyper-V role on a server. You can create one or more VMs on which you can install other server roles.
Consider installing Hyper-V on a Server Core installation to minimize resources used for the Hyper-V partition.
When you install Hyper-V on Server Core, you must manually install the hypervisor management tools.
The Hyper-V Manager console allows you to create a VM, import a VM, configure switches, and perform other management tasks.

Windows Server 2012 running Hyper-V has the following hardware requirements:

A 64-bit processor that includes hardware-assisted virtualization
A system BIOS that supports the virtualization hardware
Hardware-enforced Data Execution Prevention (DEP)

The following table describes new or updated features available in Windows Server 2012 Hyper-V and Windows Server 2012 R2 Hyper-V:

Features	Description
Dynamically expanding memory	Dynamically expanding memory maximizes the amount of memory a VM is allowed to use. Dynamically expanding memory allows you to: Specify a range of memory that can be allocated to each virtual machine. Indicate machines to which extra memory can be allocated. The total amount of memory allocated to the host and all virtual machines cannot exceed the amount of physical memory available. Set memory for: Startup RAM, the memory required to start the virtual machine Minimum RAM, the minimum amount of memory to be assigned to the virtual machine Maximum RAM, the maximum amount of memory available to the virtual machine Memory Buffer, the memory assigned to the virtual machine compared to the amount of memory needed by the applications and services running in the virtual machine A buffer is created only if there is enough physical memory available. Memory weight, the distribution of memory among virtual machines
Smart paging	Smart paging allows a virtual machine to restart when there is not enough available memory to restart the virtual machine. Smart paging uses disk resources as additional, temporary memory. A Smart page is created when: The VM is being restarted. The restart may be a result of the host restarting. There is no available physical memory. No memory can be reclaimed from other VMs on the host. The Smart page is deleted as soon as the VM has restarted.
Resource metering	Resource metering measures the assigned resources and the actual usage of the assigned resources on a virtual machine. Resource metering: Allows an Administrator to track VM statistics for billing purposes. Is enabled using the Enable-VMResourceMetering command. Monitors and generates reports on VM resource usage. Use the Measure-VM cmdlet to monitor usage on a VM. For example, to collect usage statistics for the VM named Sales1, enter: Measure-VM -VMName Sales1 You can retrieve a list of all the resources being measured and then pipe the list into a Measure -VM command to determine usage of those resources values. For example, to get usage values for all resources being used on the Sales1 VM, enter: Get-VM Sales1 \| Measure-VM \| select *
Resource control	Resource control allows you to analyze each VM’s usage of host resources. Resource control uses: A percentage of total system resources, measured by how many processors are assigned to the computer. Relative weight to determine how CPU resources are distributed between the VMs. A higher weight indicates that the VM should receive more resources.
Integration Services	Integration Services allows the VM to interact with the host system. Integration Services provides: Drivers that enable the guest OS to interact with the host and the host hardware. If you are having hardware issues with the VM, re-install Integration Services using the Integration Services Setup Disk. Settings to control how the VM and host machine interact: Operating system shutdown allows the host machine to gracefully shut down the VM when the host is being rebooted. Time synchronization allows the VM to set its time based on the host time. Data Exchange allows the host and the VM to exchange management information. Heartbeat sends a signal from the VM to the host that allows the host to determine if a VM is working properly or if a VM has locked up or crashed. Backup, referred to as a volume snapshot, enables online backups of the Hyper-V VM.
Enhanced Session Mode	On Windows Server 2012 R2, Enhanced Session Mode allows you to redirect local resources to a virtual machine session. In Enhanced Session mode, you can redirect resources using a Remote Desktop Connection session using the virtual machine bus. This eliminates the need for a network connection. Resources you can redirect to the virtual machine include: Smart cards Clipboard USB devices Audio Printers To enable Enhanced Session Mode, right-click the server in Hyper-V Manager, select Hyper-V Settings, and then select the Allow enhanced session mode checkbox under Enhanced Session Mode Policy. Windows Server 2012 R2 and Windows 8.1 are the only guest operating systems that support enhanced mode connections.

Hyper-V on Windows Server 2012 R2 introduces generation 1 and generation 2 virtual machines. All legacy virtual machines running Windows Server 2012 and earlier are now referred to as generation 1 virtual machines. The following table identifies key components of generation 2 virtual machines:

Component	Description
Supported guest operating systems	The following guest operating systems are supported on generation 2 virtual machines: Windows Server 2012 R2 Windows Server 2012 64-bit versions of Windows 8.1 64-bit versions of Windows 8
Hardware	Hardware support in generation 2 virtual machines include: Virtual SCSI controllers and virtual SCSI CD-ROMs (these replace IDE controllers and CD-ROMs). UEFI firmware replaces legacy BIOS. UEFI provides Secure Boot. Synthetic network adapters replace legacy network adapters and provide IPv4 and IPv6 network boot. There is no floppy controller support in generation 2 machines. The universal asynchronous receiver/transmitter (UART) controller requirement for COM ports has been replaced by optional UART support for debugging. Software-based components replace the components listed below. i8042 keyboard controller PS/2 keyboard PS/2 mouse S3 video Software-based components use minimal resources and make the guest operating system more secure. The following components are no longer required: PCI bus Programmable interrupt controller (PIC) Programmable interval timer (PIT) Super I/O device
Supported features	Generation 2 virtual machines support the following features: PXE boot using a standard network adapter Boot from a SCSI virtual hard disk Boot from a SCSI virtual DVD Secure Boot UEFI firmware support
Non-supported features	The following features are not supported in generation 2 virtual machines: RemoteFX Attached physical CD or DVD drive Attached virtual hard disk in VHD format Boot from VHDX file converted from a VHD file Setup mode for Secure Boot

Be aware of the following regarding generation 2 virtual machines:

You use wizards and property sheets in Virtual Machine Manager (VMM) to specify the generation of a virtual machine.
You can run generation 1 and generation 2 virtual machines together.
For generation 2 virtual machines, boot order for devices is handled by the FirstBootDevice parameter with Windows PowerShell commands.

By default, the virtual hard disk is the first device to boot. If the virtual machine has more than one virtual hard disk, the disk marked Contains the operating system for the virtual machine is booted first.
If you use a .vhd file format to create the virtual machine or the virtual machine template, the virtual machine is set up as a generation 1 machine.

You cannot change the generation of a virtual machine once the virtual machine is created.