Among the flood of Microsoft announcements about Azure in the past week -- including Redis Cache for Azure and SSD-based instances for Azure VMs -- one real standout is the general availability of Microsoft Azure Site Recovery, Microsoft's version of disaster recovery as a service (DRaaS).
In a way, the name says it all: It lets you replicate Hyper-V machines running on your site into Azure, then use those replicated machines for disaster recovery with minimal additional work. It's far from the only cloud-based solution of its kind, though.
The most obvious competitor is VMware's vCloud Air Disaster Recovery, which premiered back in April. Conceptually it's the same: Those running a given hybrid cloud infrastructure -- in this case VMware vSphere -- can make live replicas of running servers onto VMware's public cloud. In the event of a local failure, the cloud instance takes over.
Most of the choice in DRaaS comes down to which virtualization and cloud infrastructure you've already committed to, VMware or Microsoft -- if indeed if you've made a commitment. Apart from that, the differences revolve largely around flexibility of pricing. Microsoft's offering is more straightforward -- a flat per-VM, per-month replication cost that starts at $27 -- but it's less flexible since it only provides an average of one protection cycle per day. That cost, by the way, is an extension of the preview pricing and is set to rise to $54 per month, per instance on Dec. 1.
VMware's pricing is more complex and requires a larger upfront investment, but it's also more nuanced. For $795 per month, a certain amount of storage, networking, virtual CPUs, and RAM are included. Additional amounts of each are available on a per-month basis. Users can also set highly granular recovery intervals, anywhere from 15 minutes to 24 hours.
Cloud-based disaster recovery started to really take off two to three years ago, driven by a slew of rising needs -- not least of which is how complex and demanding it can be to get any disaster recovery plan to work. The solutions that have popped up have revolved largely around VMware -- such as Bluelock's solutions, powered by Zerto Virtual Replication, which can perform DR both to an existing cloud or between clouds. VirtualSharp (now called Unitrends) offers another VMware-compatible DR system, with an emphasis on business-specific needs like regulatory reporting.
If Azure Site Recovery stands out from this pack, it's not only because it's a Microsoft Azure solution, but because of how Microsoft thinks of Azure plus Windows Server as a hybrid solution. This is clearest if you look at one feature in particular: The ability to have a Hyper-V cloud instance resurrected on local hardware as well.
Unfortunately, that feature is only available at a per-VM cost that's around the same as the local-to-cloud version of the service. But it's evidence of how Azure and Windows Server are meant to compete with the rest of the cloud and server market by being malleable and interchangeable.