Virtualization provides many benefits, such as hardware independence, efficient use of resources and
scalability in private cloud scenarios.
It also provides flexibility when you move virtual machines across virtualization infrastructures.
In the past, when administrators virtualized domain controllers, they had to be familiar with ads
specific requirements so that they could avoid adding risk to the ads infrastructure when using virtual
domain controllers.
Consider the following best practices Avoid single points of failure.
Ensure that you have at least two virtualized domain controllers per domain on different virtualisation
hosts, which reduces the risk of losing all domain controllers if a single virtualisation host fails.
Also, diversify the hardware, storage networks and storage systems.
Ensure that you maintain domain controllers in different data centers or regions to reduce the impact
of disasters.
Verify time services.
Ensure that all computers, including the hypervisor host and domain controller guests, are participating
in the same time.
Services.
Infrastructure.
Also ensure that the time on the host and on the guests does not differ.
Use virtualization technology that allows for virtual machine generation identifiers only virtualization
infrastructures that support the new virtual machine generation identifiers also support the safeguards
and cloning of virtual domain controllers.
Use Windows Server 2012 or later as the guest operating system for virtual domain controllers only.
These versions support the safeguards for virtual domain controllers, avoid or disable checkpoints.
If the virtualization host or the guest operating systems of the domain controllers do not support the
safeguards for virtualizing domain controllers, disable the possibility of creating checkpoints.
You can do this by using a pass through disk instead of a virtual hard disk.
For example, when there is support for the safeguards, use a virtual hard disk to support cloning
but avoid using checkpoints.
Strive to improve security by ensuring that the virtualization administrators are as trusted as your
domain admins.
Consider taking advantage of cloning.
Cloning can be a deployment or a recovery strategy.
It helps to provide a fast and simple way to create many domain controllers in a short time clone in
batches of ten at a maximum.
Do not start more than ten new clones at the same time because the file replication used to persist,
will allows only ten replication connections at the same time.
Consider using virtualization technologies that allow you to move virtual machines across site boundaries.
This can be beneficial in your deployment and recovery strategies.
For example, you can create ten clones in a central location and then move them to remote offices during
off peak hours.
Adjust your naming strategy to allow for domain controller clones.
For example, allow Clone Domain controllers to retain the first eight characters of the source domain
controller name and then attach cloning and end.