There are two main reasons why an organization might choose a virtual tape library over a deduplication array. One reason is price. Virtual tape libraries exist at a variety of price points, whereas deduplication arrays tend to be higher-end solutions.
The other reason why an organization might choose a virtual tape library over a deduplication array is for compatibility purposes. Virtual tape libraries emulate physical tape drives or tape libraries and can therefore be seamlessly integrated into an existing backup infrastructure. As such, it is typically going to be easier and less expensive to add a virtual tape library to an existing backup architecture than to try to add a deduplication array.
Integrated backup appliances seem to be used primarily in medium-sized organizations (organizations with a few hundred employees) and by individual workgroups or departments in large organizations.
Integrated backup appliances aren't commonly used in small organizations because these types of organizations typically use backup solutions that are far more basic. At the other end of the spectrum, enterprise-class organizations tend not to use integrated backup appliances because those appliances do not scale well.
This was first published in January 2014