Why is everyone talking about IO filters?

At this year’s VMworld, a relatively little-known feature of vSphere is getting a surprising amount of attention. The VMware vSphere APIs for IO Filtering (VAIO) aren’t as well-known as other storage features like Virtual Volumes or Virtual SAN, but they’re very important for VMware vSphere as a hybrid cloud platform, especially with respect to cloud-based services for disaster recovery (DR) and business continuity (BC).The new attention to VAIO is due to a number of well-known data protection vendors announcing that their solutions will begin to use the API. This article doesn’t take a deep dive into the API itself (there’s an excellent technical introduction in this blog post). Rather, the point of this discussion is to explain why IO filters are increasingly important to enabling DR/BC services and why the vendors in this space are updating their products to use the IO filters API.