With cross-premises connectivity and Active Directory services, you can really open up
the services that can be placed in Microsoft Azure. I see many organizations using a
hybrid approach. Often, they start with testing and development in Microsoft Azure,
and once the technology is proven and trusted, it is expanded. Remember to look
constantly at what new capabilities are available. Although initially you could, for
example, deploy an IaaS VM running SQL Server databases, over time those databases
may be able to be moved to SQL Azure instead, reducing your management overhead.
An interesting use case that I have seen is to use Microsoft Azure as the disaster-
recovery site. At the time of this writing, Microsoft Azure can be the target for
replication from many sources, including Hyper-V, VMware, and even physical
systems via Azure Site Recovery (ASR). This protection is at an OS level and not
application “aware.” In the case of Hyper-V, the replication is performed at the VM
level via Hyper-V Replica, and for VMware and physical systems, the replication is
achieved through an in-OS agent that captures writes to the filesystem and sends
them to the target replica. While this type of VM/OS replication is fairly simple and
generic enough to be used across many types of services, it may not be the best option
because it is not application aware. You need to look at each service and how to
replicate. Here are some approaches. Keep in mind that there is not one right answer;
it will depend on the workload.
For Active Directory, deploy domain controllers to Microsoft Azure and use Active
Directory multimaster replication to keep the Microsoft Azure domain controllers
up-to-date.
For file data, one option is to use Distributed File System Replication (DFS-R) to
replicate data to a file server running in Microsoft Azure IaaS. Distributed File
System Namespaces (DFS-N) could be used to give users transparent access to the
data. Another option is to use StorSimple, which will also store data in Microsoft
Azure. In the event of a disaster, a virtual StorSimple appliance is started in Azure
and can enable access to the Azure-backed data. Windows Server 2016 introduces
Storage Replica, which, via its asynchronous replication, or possibly synchronous
replication, if latency was low enough via ExpressRoute, replication configuration,
may be a great fit to copy all kinds of data. Another option is to copy data
periodically using Robocopy or PowerShell.
SQL databases can be replicated using SQL Server AlwaysOn, which should be used
in asynchronous mode. This requires stretching a cluster between your premises
and Microsoft Azure.
SharePoint instances are mainly SQL Server data. Therefore, deploy SharePoint
instances in Microsoft Azure and use SQL Server AlwaysOn to replicate the
SharePoint data. For data not stored in SQL Server, use another process to
replicate filesystem configuration periodically or as part of a change-control
process.
Exchange and Lync are supported to run in IaaS with various caveats. However, the