The  move toward widespread virtualization is usually accompanied by new systems architecture. This would address load balancing, failover and high availability, and also support WAN-based access for remote offices and workers (e.g., sales people who work from home).   Because it's designed for efficiently replicating data from one site to another, this architecture streamlines disaster recovery.

Why is this? The data in a virtualized environment usually encompasses virtual machines (VMs), a configuration database and user data. The size of this data depends on your environment – whether it’s desktop or server virtualization. Beyond that, other components of the virtualized environment, such as hypervisors and connection brokers can be easily put in place to accommodate the replicated data from the main site to a DR site. 

Other issues you need to consider when replicating data to your DR site include: network bandwidth, size of your data files and deciding if your DR environment will be a hot or cold site.   Your choice of operating systems makes little difference in terms of DR, because the operating system is part of the overall backed-up data that is sent to a DR site.

In a “traditional” client-server environment without virtualization, backups are usually only done for the actual user data (especially if the data is on a network share) and not for operating systems or applications.  And if your end user devices are PCs, backing up individual PC operating system environments, including individual user customization can be daunting if not impossible.  

Even if your IT department keeps a golden image of the applications loaded on end-user PCs, it typically doesn’t include  customizations.  This is where virtualization can definitely help; each user’s environment is a virtual machine which contains all applications and any customizations (assuming the user is using a persistent desktop). 

From the standpoint of server virtualization, a complete back-up of your server VMs should be easier to execute because the VMs will likely reside on some type of centralize storage.  Most storage systems support storage replication which makes this really easy to accomplish for back up proposes.   The replicated data can be easily sent off site via high speed network to a DR site. 

One of the problems I’ve  seen with sending large amounts of data across the network is the time it takes – some sites don’t have the network bandwidth to handle the data.  This is where WAN optimization becomes your friend! WAN  optimization will let you send large amounts of data across potentially long distances by applying compression, de-duplication and data packet optimization features regardless of the transport protocol or latency sensitivity. This boosts WAN performance and reduces costs by optimizing existing bandwidth. Keep in mind different WAN optimization solutions work better with certain types of data, it's important to do your homework – and perhaps a pilot – before you invest in this technology.

Finally, you need to think about how you configure end user systems to access your DR site if your main site goes down or becomes inaccessible to your staff.