1. Planning your virtual machines
Each situation in which you might create a virtual machine is
different. Therefore, the decision to create a virtual machine must be
based on the needs of the particular situation and the policies of your
organization. Because of the many variables, there is no best practice
for how many or what types of virtual machines should be created. For
example, a desktop support technician might maintain a virtual
mausoleum of operating systems for large environments where multiple
Windows versions are used. This repository can expand quickly when x86
and x64 variants are considered.
A Hyper-V virtual machine has a virtualized hardware inventory of
all the components, like a standard Windows 8–based computer: disk,
memory, network, and processing. The virtual machine creation process
defines how these virtual elements will be configured for the virtual
machine.
When you create the virtual machine, you are asked to provide
several crucial pieces of information: the name of the machine, where
the files will be stored, the amount of memory assigned to it, and the
network connection options. Think each of these through before you
start creating any virtual machines so that you have a consistent and useful plan in place. This will make troubleshooting easier.
Establishing names and locations
The virtual machine name and location are very important; the name
of the virtual machine should match the computer name assigned to it.
Consider creating
a nomenclature that makes sense in your organization. For example, if
computer accounts have a predictable naming pattern, follow it when
deploying Hyper-V virtual machines. It might also be worth establishing
a naming policy by which you designate a name that identifies it as a
virtual machine name, assuming the computer name is the same. This can
be something as simple as adding a “-V” to the name or some other
addition that makes sense in your organization. If non-Windows systems
are used extensively, consider using fully qualified domain names (FQDNs) for these hosts.
Note
GIVE VIRTUAL MACHINES THE SAME NAMES AS COMPUTER
Sometimes, an issue will occur on a network with a virtual machine
that will require you to track down what happened. Further, with the
virtual machine running in Windows 8, it’s possible that certain ways
of identifying a system are more difficult with a virtual machine. One
example is serving DHCP from an unauthorized server that is a virtual
machine. It can be difficult to track these down, and ensuring that the
name of the virtual machine in Hyper-V Manager matches the guest virtual machine will help immensely.
For the location of the virtual machine files, the C drive is used by default in a designated path for Hyper-V
in the C:\ProgramData\Microsoft\Windows\Hyper-V folder. If other drive
letters or hard drives are added, they can be used as fixed local disk
resources. This includes an iSCSI target that can be provisioned as a
drive letter and formatted in Windows. Network resources can also be
used with SMB 3.0, the Windows 8 and Windows Server file-based network
protocol.
Understanding memory availability
Always consider the free space involved. Many Hyper-V administrators
avoid placing virtual machines of any quantity or size on the C drive
of the Windows 8–based computer with the Hyper-V feature enabled
because of the risk of the drive filling to capacity and causing issues
with both the virtual machines and the computer running Windows 8.
Note
WHERE VIRTUAL MACHINES RESIDE
Storage will be discussed in the next lesson in greater detail, but
you should give some thought to where the virtual machines will reside
within Hyper-V. For Windows 8 systems, using high-performance removable
storage components, such as solid state drives (SSDs), as a container for virtual machines, is a good idea. The virtual machines are portable on high-performance storage and can’t fill up the C drive of the Windows 8–based computer.
The memory
options are important, and the shared resources should be considered.
Depending on the amount of memory installed on the computer running
Windows 8, there might be a maximum amount of memory that a virtual
machine can use. The Hyper-V feature can be enabled only on computers
running Windows 8 with 4 GB of memory or more, and there is a reserved
amount for Windows 8. For the 4 GB minimum, 1,882 MB of memory is made
available to Hyper-V for virtual machines. All virtual machines that
are simultaneously turned on will work from that pool of memory, and
virtual machines that are turned off will not consume memory.
When you configure the storage for a new virtual hard disk, the default format with Hyper-V on Windows 8 is VHDX. VHDX is a virtual disk format used in Hyper-V that expands on the popular VHD format used by earlier versions of Hyper-V.
The VHDX file format supports virtual disk files up to 64 terabytes
(TB) in size, a substantial improvement over the VHD maximum of 2 TB.
The size for the VHDX file is set to 127 GB by default, which is
fine for most Windows operating systems. You should consider your
environment to determine if that is too large or too small as a
maximum. One key technology to assist in this decision is thin
provisioning, which will have the virtual disk consume the space used
within the virtual machine. Thin provisioning won’t provision the
entire 127 GB at once, yet it could grow to that size or larger with
snapshots, so keep this in mind in the provisioning process.
For new computers running Windows 8, there is usually a large amount of storage
available for systems running traditional rotational storage. However,
if the computer running Windows 8 is running an SSD, the total
available space can be comparatively limited. Keep this in mind when
provisioning virtual machines on Windows 8 systems.
Planning installation options
Use these tips for Hyper-V virtual machines to make the virtualized
media management easy to use and to avoid duplicated instances of
(potentially) large files such as CD/DVD ISO files:
-
Have one designated location for virtual media. This can be local
(such as C:\ISO) or on a network resource. If multiple Windows 8–based
computers will have the Hyper-V feature enabled, it might be worthwhile
to provision a dedicated storage resource for the virtual media for a
workgroup to share.
-
Use a simple name for the files, such as Windows8.iso.
-
Keep only the files you need.
-
Don’t mix distributions of operating systems, such as a TechNet
license distribution and possibly the company enterprise licensing
media (and licensing).
The physical CD/DVD drive and network and virtual floppy
disk resources can be used. For most situations, the virtualized media
on a CD/DVD ISO file will be the most popular installation type.
