Difference between revisions of "Creating Hyper-V Virtual Machines"

Revision as of 16:28, 12 January 2009

The key to virtualization is the ability to create virtual machines. As such, the objective of this chapter is to focus on the steps involved in creating virtual machines using Hyper-V and the Hyper-V Manager.

Launching the Hyper-V Manager

The first step in creating a new virtual machine is to launch the Hyper-V Manager tool. This can either be run directly on the Hyper-V hosts system, or on a remote system which network access to the host by selecting Start -> Administration Tools -> Hyper-V Manager.

If connecting from a remote system, it will be necessary to connect to the Hyper-V host from within the Hyper-V Manager before creating new virtual machines. This can be achieved by selecting the Action -> Connect to Server... menu option.

To begin the virtual machine creation process, ensure that the correct Hyper-V server is selected from the left hand panel and click on the New link in the Actions panel. From the resulting menu, select Virtual Machine... to invoke the New Virtual Machine Wizard.

Creating a Default Virtual Machine

The New Virtual Machine Wizard will work through a series of steps to define the new virtual machine. If, at any time, the Finish button is pressed, the wizard will create a new virtual machine using default values. This will create a virtual machine with 512MB of memory, one network adapter, one legacy network adapter, a CD drive and a virtual hard disk located in the default location on the host file system.

To configure a virtual machine to a specific specification, click Next to proceed to the Specify Name and Location screen.

Virtual Machine Name and Location

The Specify Name and Location screen provides the opportunity to define a name for the new virtual machine and specify the location where the configuration files will be stored. The location field is populated with the default location, although this may be changed to any location accessible to the host system by selecting the option to Store the virtual machine in a different location:

It is important to keep in mind that the location specified here is solely for the configuration files and does not specify the location of any virtual disks which will be assigned to the virtual machine.

Once the information is complete, click Next to proceed to the memory configuration step.

Configuring Virtual Machine Memory

As the name suggests, the Assign Memory screen allows the amount of memory allocated to the virtual machine to be specified. The amount to allocate will depend on a number of factors including:

- The memory requirements of the guest operating system which will run inside the virtual machine.

- The amount of physical memory present in the host system.

- The requirements of other virtual machines which will run concurrently with the virtual machine currently being created.

Note that the amount of memory allocated at this stage may be modified at a later date is the selection made now proves to be problematic.

Once the memory allocation has been made, click Next to configure Networking.

Configuring Virtual Machine Networking

Virtual machines are assigned a network adapter which allows the guest operating system to connect to a virtual network. Virtual networks are configured outside of the virtual machine creation process and can be configured using the Virtual Network Manager... link in the Hyper-V Manager Actions panel. Virtual networks can be external (the virtual machine has access to the external network), internal (virtual machine can connect to other virtual machines on the physical host and also with the physical host itself, but not the external network) or private (communication only between virtual machines on the same physical host, no communication with physical host or external network). For an overview of virtual networks refer to the chapter entitled Understanding and Configuring Hyper-V Virtual Networks.

Either select a pre-existing virtual network from the drop down list, or select Not Connected if there is to be no network connection, or the connection is to be configured at a later time. Click Next to proceed to the hard drive configuration screen.

Configuring a Virtual Hard Disk

The guest operating system running in a virtual machine will typically require access to disk storage both to contain the system files and any user data. The first requirement is that the storage to be used by the virtual machine must be accessible to the host system. In terms of storage access, Hyper-V supports Direct Access Storage (DAS) drives including IDE, SATA, SCSI and SAS, and Storage Area Network standards such a fiber channel and iSCSI.

Assuming that the storage is connected to the host system in some way there are two choices as to how a virtual hard disk is made available to the virtual machine:

- Virtual Hard Disk (VHD) - The virtual hard disk created as a file which resides on a storage colume which is accessible to the host server. Disks can be dynamic expanding (starts small and grows as space is required) or fixed in size. The maximum size of VHD is 2040GB.

- Pass-through disk - A pass-through disk assigns a physical disk drive to the virtual machine enabling the guest operating system to perform raw read and write actions on the disk. Hyper-V imposes no constraints on the size of a pass-through disk.

Although the New Virtual Machine wizard does not provide the option to