We have recently completed a Disaster Recovery test for a customer. They use Virtual Desktops and Servers, and data is replicated to the DR site by the underlying storage arrays.
For this test, we used VMware Site Recovery Manager to perform a planned migration of virtual server workloads to the DR site (i.e. a graceful, planned failover). VDI desktop pools were already provisioned to save time in DR failover. After failover, systems at the primary site were powered down.
Failover occurred on a Friday evening, and the users returned to work on Monday as usual. Since their desktops are virtual, there was almost no user awareness that the primary site was down and that they were using desktops running in a different datacenter to usual. This is really the ultimate proof that the DR infrastructure and strategy work!
Production systems were then powered on, and replication reversed (using Site Recovery Manager reprotect for the virtual servers) whilst the users continued running from the DR site for the remainder of the week.
After a week of running from the DR site, another planned migration was performed on the Friday evening, returning workloads to the primary site. Users again returned to work on Monday with no operational impact.
Finally, a last replication reversal / reprotect was performed and the systems were back to their original state.
To summarise, we were able to migrate production workloads, including hundreds of virtual desktops and servers from one data centre to another in just a couple of hours. We were then able to migrate them back a week later in the same fashion. Users were largely unaware that this had occurred, and therefore the organisation can now have real confidence that their systems can survive a disaster.