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VMware ARM technology has the potential for immense success in markets that are demanding better management of increasingly widespread ARM CPUs. But VMware must navigate the unique needs of IoT, telco and corporate data centers to find compelling use cases.
When VMware announced the ESXi hypervisor on Advanced RISC Machines (ARM) CPUs at VMworld 2018 in Las Vegas, many people immediately thought of a hypervisor on platforms like Raspberry Pi. Though this $35 computer provides a proof of concept, this likely won't be the path for real-world VMware ARM adoption. Expect instead that embedded systems with multiple ARM CPUs will have a hypervisor rather than more physical ARM CPUs.
To set the stage, examine the differences between the x86 CPU in your laptop and the ARM CPU in your phone. Intel x86 is a powerful, high-performance CPU that suits intense work and costs hundreds of dollars per CPU. The ARM CPU is designed for low power and simplicity at a low cost; performance is secondary. If there's a CPU in something that doesn't have a screen and a keyboard, it's most likely an ARM CPU. Your Wi-Fi router and modern washing machine probably both have ARM CPUs, and your car might have several.
The proliferation of ARM CPUs inside a multitude of devices has led to the need for a hypervisor. Another important milestone with x86 CPUs and virtualization is the addition of hardware features in the CPU to support virtualization. There are ARM CPUs with the same sort of virtualization extensions that enable VMs to run with native hardware performance. These extensions have enabled open source KVM and Xen hypervisors to support ARM for some time, so the VMware ARM hypervisor won't be the first to market.
It's essential to set some expectations for the VMware ARM announcement. VMware didn't announce a product, but it showed a real customer using its ESXi ARM technology. The quick glimpse showed vSphere managing a single ARM system inside a wind turbine that ran four VMs.
A significant feature of the ARM system is management through vSphere. Administrators can now bring the broader VMware virtualization management suite to bear, which can simplify management for a large number of virtualized ARM machines. Hopefully, vSphere features such as vMotion, the distributed resource scheduler and high availability are included in the finished product. Ideally, VMware's NSX network virtualization will also deliver secure networking to the edge locations where these clusters run.
VMware ARM follows in the footsteps of VMware virtualization
VMware's rise followed an explosion in the number of physical x86 servers in data centers. At the start of the 21st century, organizations deployed dozens of physical servers that ran Windows or Linux for all new applications. A similar explosion is now happening in embedded systems with ARM CPUs.
A smart car might have had a single embedded computer five years ago; now, it has half a dozen different computers that all run lightly loaded ARM CPUs. That might be the ideal situation for a single beefy ARM computer with a hypervisor. The same is true in industrial automation and monitoring. All kinds of systems are adding multiple ARM-based computers.
There are a number of vendors bringing ARM CPUs to the corporate data center, which is VMware's forte. It will be interesting to see whether a hypervisor helps these vendors. They tend to solve problems with a sea of small ARM computers running at high utilization, which doesn't suit virtualization any more than existing high-performance compute on x86. This points to why VMware ARM use cases include more edge and IoT devices rather than the data center.
Telecommunications companies are currently undergoing a significant change from the adoption of network functions virtualization, which makes VMs deliver functions that were previously delivered by dedicated hardware devices. Dedicated hardware was often based on ARM systems, so the ability to use an ARM VM to perform the exact same function is appealing because there is no redevelopment necessary for the function.
ARM CPUs are also popular in places where space and power are at a premium, such as cell towers and telco interconnect cabinets. VMware might eventually offer fleets of ARM-based ESXi systems managed from a central console to meet this demand.