AWS Outposts vs. Microsoft Azure Stack


AWS Outposts – AWS Moves into the On-Premises Hardware Space

Amazon Web Services is making its latest push into yet another part of the IT space with its imminent move into the on-premises hardware business.

At re:Invent last month, AWS took a major leap forwards into the world of data centers and announced Outposts, an on-premises data center system that will allow its customers to have AWS hardware and services on-premises. AWS has already been working in partnership with VMware over the last two years, introducing VMware virtualization software to the AWS public cloud last year. The new service, AWS Outposts comes in two forms: the first, an extension of the existing VMware Cloud service, allowing users to run VMware private cloud software on Outposts; the second allows them to use the native AWS APIs.

At the AWS re:Invent partner conference, AWS CEO Andy Jassy said the partnership with VMware was aimed mainly at enterprises that have been slow to migrate to the public cloud. “The longer they wait, the deeper the ditch gets,”, he said. AWS Outposts allows enterprises to run compute and storage on-premises, while simultaneously benefitting from a seamless integration with AWS applications and services. “Customers order racks that have the same hardware that AWS is running on our regions,” Jassy said.

“Customers are telling us that they don’t want a hybrid experience that attempts to recreate a stunted version of a cloud on-premises, because it’s perpetually out of sync with the cloud version and requires a lot of heavy lifting, managing custom hardware, different control planes, different tooling, and manual software updates. There just isn’t a lot of value in that type of on-premises offering and that’s why these solutions aren’t getting much traction,” said Andy Jassy, CEO of AWS. “So we started with what our customers were asking for and worked backwards. They told us they want an extension of their AWS or VMware Cloud on AWS environment on-premises, using the same hardware we’re using, the same interfaces, the same APIs, the same instant access to the latest AWS capabilities the minute they become available, and they don’t want to manage hardware or software. So, we tried to reimagine what customers really wanted when running in hybrid mode, and developed AWS Outposts.”

The service is currently in private preview mode and will become generally available to the public in the second half of 2019, according to AWS.

Outposts is not the tech giant’s first move into the private cloud. Previously, it offered “Snowball Edge”, which was a hardware device capable of running AWS software designed for harsh conditions, such as the factory floor, and optimized for compute.

The On-Premises Hardware Landscape

AWS’ new service is aimed at capturing enterprises that want to bridge the gap between their public cloud and private data centers. It joins several existing major cloud provider services in the space: Microsoft’s Azure Stack, which runs Azure infrastructure and platform software on on-premises hardware, and Google’s GKE On-Prem, which was launched this summer and provides “the Google Kubernetes Engine experience directly in your data center”.

Microsoft Azure Stack

Microsoft was ahead of the curve when it launched Azure Stack at its Inspire event in July 2017. In order to do so, it partnered with three of the industry’s biggest server vendors: Lenovo, Hewlett Packard Enterprise and Dell EMC. Some in the industry have said that Outposts is merely a validation of Microsoft’s strategy with Azure Stack and that because they were the pioneers, they will win in the space. Others predict the opposite outcome, with AWS dominating.

Microsoft’s Azure Stack allows customers to spin up the same cloud platform the company runs in its public cloud inside a private, on-premises data center. It is sold as an integrated system of software and validated hardware, letting “you build, deploy and operate hybrid cloud applications consistently across Azure and Azure Stack”.

Microsoft recently announced that it has joined forces with Cisco and Signal Alliance to continue to deliver the Azure Stack solution. Microsoft owns the software while Cisco and various other vendors support with their proprietary hardware. The move was unveiled at a practical workshop in Nigeria to an audience which included top business execs in the banking, insurance, telecom, oil and gas sectors. Participants were shown a demonstration of how the hybrid cloud computing platform works for edge and disconnected scenarios to address latency and connectivity challenges, in addition to how Azure Stack can help government agencies and businesses leverage cloud capabilities yet still ensure regulatory requirements around data residency.

Key Features

  • Azure Stack is available in 4, 8 and 12 nodes; all nodes run Windows Server 2016 Hyper-V Core with the VMs that deliver Azure infrastructure sharing the space with tenant VMs
  • You can lose up to two nodes in a cluster and still run because Azure Stack uses three-way mirroring, storing three copies of each data slab on three different nodes
  • Expansion with more nodes to an existing stamp is in the works, as is joining a new stamp to an existing stamp
  • All-flash configurations are available (with SSD as the capacity storage tier, and NVMe as the cache layer)
  • Storage is provided via Storage Spaces Direct, which combines local storage in each node (HDD, SDD, NVMe) for high performant, tiered and resilient VM storage
  • Internal networking is RDMA (typically 50 Gb/s or faster between each node)
  • The file system is Resilient File System (ReFS)


  • You don’t buy Azure Stack from Microsoft, but from one of several vendors: Cisco, Dell EMC, HPE or Lenovo are among the integrated system partners.

Azure Stack is not a Hyper-V platform which you can migrate your current workloads to, nor can you run it on your own hardware. It is only offered from the select vendors in place. Some of the other downsides are detailed in this informative post. The Azure Stack offering is a turnkey, appliance-like solution that you and your choice of hardware vendor will install and integrate into existing environments, allowing you to then deploy workloads to it.

You have to update Azure Stack at least every three months to ensure continued support and keep Stack in sync with public Azure.

There are two primary modes for deploying Azure Stack, either fully disconnected (useful for remote offices and locations) or Internet connected. For the first option, you are charged based on the number of CPU cores in your Stack; whereas the second option allows you to use the pay-as-you-go model in which the usage of IaaS and PaaS services are reported back via your Azure AD tenants in public Azure and charged the same way as regular Azure usage.

Azure Stack’s primary promise is that it offers a public Azure in your own datacenter. You can provision a variety of IaaS and PaaS services, Azure Functions (serverless) and App Services (web applications). Microsoft and third-party offers in the Azure Marketplace can also be downloaded and offered to your tenants. It is truly a hybrid cloud, allowing developers the luxury that anything you write to deploy on public Azure should run in Azure Stack without change in a DevOps model.

AWS Outposts

The two variants of AWS Outposts are:

  • VMware Cloud on AWS Outposts: this offering enables the VMware Software-Defined Data Center (SDDC) – compute, storage, and networking infrastructure – to run on-premises and be managed as a Service from VMware Cloud on AWS. It is aimed at customers “who want to use the same VMware control plane and APIs they’ve been using to run their infrastructure” already.
  • Native AWS Outposts: this will initially begin with a new integrated offering from VMware called VMware Cloud Foundation for EC2, which “will feature popular VMware technologies and services that work across VMware and Amazon EC2 environments”. It is aimed at customers” who prefer the same exact APIs and control plane they’re used to running in AWS’s cloud, but on-premises”.

In both instances, AWS will be responsible for delivering the racks to customers, installing them (if needed), and handling the maintenance and replacement of racks. These AWS Outposts will either be an extension of a customer’s Amazon VPC (in the closest AWS Region to the customer) or any other AWS service.

Key Features

  • AWS Outposts allows you to run AWS components in your datacenter, beginning with EC2 and EBS
  • You can start with as little as one node and scale out
  • You can order a wide range of compute and storage options, including just one or more server, or quarter, half and full rack units
  • AWS’ networking can use NXS (to integrate AWS Outposts with your Layer 2 network), VMware AppDefense (to protect known “good applications”), and VMware vRealize Automation (for provisioning of workloads)
  • You don’t need to rewrite applications; hardware and software infrastructure is shared across the private and public cloud, allowing you to build and run modern, cloud-native applications anywhere


  • Management of AWS Outposts can be performed via the existing AWS consoles, or the standard APIs currently available in AWS
  • AWS is fully managing the hardware and software updates and offering full support of the box
  • AWS Outposts also allows you to select the VMware Cloud as your management plane

Comparison & Conclusion

Some of the differences between the services include:

  • With AWS Outposts, you can start at one node; with Azure Stack, the minimum is four nodes (except for ADSK). Ultimately there won’t be redundancy if one node fails, however, it is possible to include a sizeable amount of storage and CPU in one node these days (96 cores, 2TB of RAM and 1PB of storage);
  • AWS owns the complete hardware and software stack (despite its partnership with VMWare); Azure Stack works with several OEMs. The simplicity of ownership makes testing and deployment simpler and more predictable (Microsoft will have to verify any update on all their system variants), a highly useful feature when you want to introduce complex new features such as networking capabilities that depend on hardware acceleration;
  • You can order AWS Outposts via the AWS console, making it extremely simple to deploy. With Azure Stack, you have to first work with one of its partners and move through the procurement and deployment stages;
  • Unlike Microsoft, AWS offers a full management service (including automatically managing updates).

Integrating any solution into a data center is difficult, and this type of solution involves several major challenges. Azure Stack was in gestation mode for around three years, rolled out several technical previews over that time and continues to evolve today. Scaling Azure down for just a handful of nodes is difficult. Its App Service and DB as a Service started to only really be viable this year while AWS says that EC2 and EBS will be available at the time of launch. It remains to be seen if they will be able to achieve that.

Who will end up dominating the space? Will Microsoft be able to capitalize on its early lead? Will Outposts in fact be the next wave? Some are saying that AWS has already “eaten VMware’s breakfast, lunch and dinner”, and question who will be next…

Meanwhile earlier this year, Amazon also partnered with Cisco to allow enterprises to run Kubernetes applications that move freely between private clouds and the AWS public cloud. Containerizaton offers portability between on-premises applications and those in the public cloud, but it can be difficult to deploy and manage. Cisco’s partnership with AWS is aimed at providing an easier hybrid solution, making it more straightforward for organizations to run production-grade Kubernetes on-premises and to manage containerized apps compatible with the AWS public cloud.

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