At last it’s here: After a prolonged gestation with three public previews, Microsoft has announced the release of Azure Stack. You can now. Complete hardware and software solutions will ship in the next couple of months, when Microsoft completes certification.

Bringing the public cloud to on-premises data centers was always going to be a big task, and Microsoft won’t be delivering the entirety of Azure in this initial release. In fact, don’t expect to ever see all of Azure in Azure Stack, as there are plenty of Azure features that rely on the scale of cloud. That said, there is more than enough to start with, with support for core Azure IaaS and PaaS features. Other optional elements include Azure’s App Service and its serverless Functions.

You’ll have to wait a while for some of the more anticipated features: Azure Container Service and Microsoft’s second-generation PaaS, Azure Service Fabric. Although leaving PaaS features like these for later updates makes sense for Microsoft’s roadmap, it’s a pity they didn’t make it to the initial release, as it perpetuates the myth that hybrid cloud solutions are for IaaS. Still, by leveraging a modern container-based devops model and a continuous integration pipeline, it’s easy to treat IaaS as a custom PaaS, especially with Azure Stack’s support for Chef, Docker, and Mesos.

Cloud-consistent devops on premises

Azure Stack is “cloud consistent,” meaning that code that runs on an on-premises instance will also run on Azure, using the same Azure Resource Management descriptions as your on-premises apps, and allowing you to deploy in Azure just by changing your devops endpoint. It’s an approach that should help deliver effective hybrid cloud applications, moving your code to where your data is (keeping sensitive data on-premises for regulatory compliance, and using cloud resources to add performance and scale where appropriate).

, along with Dell and Lenovo. HPE’s ProLiant for Microsoft Azure Stack isn’t cheap: You’re looking at an investment of at least $300,000 for a base configuration. That’s not surprising when you break down the contents of a rack, which is based on the ProLiant DL380 Gen9 servers. Each rack has four to 12 DL380 Azure Stack nodes, with a single DL360 handling hardware management. Three switches handle rack and server interconnects, while integrated power distribution units can be configured to suit your compute and storage requirements.

With up to 12 compute and storage nodes per rack, and up to 88TB of storage per node, there is plenty of flexibility in HPE’s Azure Stack offering, which is surprising for something that’s built around a very limited set of hardware options. That’s good, as it gives you the option of upgrading elements of a rack going forward, allowing it to expand with your requirements. It will be interesting to see what configurations become most popular.

Alternative options will initially come from both Dell EMC and Lenovo, with Cisco and Huawei to follow. include a half-rack-height 25U unit, as well as a more familiar 42U rack. Like HPE, Lenovo is using familiar servers as the basis of its compute and storage nodes. It’s an approach that should keep costs to a minimum, as there already are economies of scale in place, especially as Azure Stack vendors will need to stockpile enough components to cover the entire support lifecycle of a rack. A smaller Azure Stack implementation should fit in well with some of Microsoft’s suggested deployment scenarios, especially where you’re putting a replica of your cloud services in a space- and bandwidth-constrained environment, such as a cruise ship or a mine.

Having a consistent hardware basis, even if from different vendors, makes a lot of sense for a platform like Azure Stack. Microsoft has committed to frequent updates to Azure Stack, which are unlikely to match the cadence of the public cloud, but will be significantly faster than you’re used to with Windows Server and its application stack.

One thing remains clear: Running Azure Stack, like the Azure Pack before it, won’t be anything like running Windows Server. With certified hardware, you can ignore your machines and focus on your applications and the Azure Stack portal. You’ll need to treat Azure Stack like a cloud to get the most from it—a cloud that’s in your data center.