Private, public and hybrid IaaS cloud offers you new, flexible deployment options for your virtual machines. By utilizing a central catalog containing your templates, you can deploy virtual machines with a simple mouse click. If your using some kind of catalog synchronization tool (VMware offers Cloud Connector for this), you can synchronize templates throughout all different on- and off-premises clouds you’re using.
Another nice feature when talking about private, public and hybrid cloud is workload mobility. In a cloud scenario this means you can move your workload (virtual machines) from one cloud to another cloud, from private to public, from public back to private and also between public clouds. When you choose to run DTA workloads in a public cloud (and not in your on-premises environment), workload mobility enables you to move or copy a workload from your on-premises virtual infrastructure/cloud to the public cloud provider.
Another example is when you want to switch from public cloud provider, part of your exit strategy is to move the workload from one cloud provider to the other. For VMware Cloud Connector is the workload mobility tool, Microsoft has App Controller in place for this.
Workload mobility and Microsoft licensing
Let’s look at these use-cases/scenarios from a Microsoft Windows OS licensing perspective (there’s some information about Microsoft application licensing at the end of the article). As you might know, in a virtualized environment Microsoft Windows licensing is linked to your physical servers:
- One standard license allows you to run 1 virtual machine or so called Operating System Environment (OSE) per physical server;
- One enterprise license allows you to run 4 virtual machines (OSE) per physical server;
- A datacenter license allows you to run unlimited virtual machines (OSE) but is payed per CPU socket and not per server.
In a public cloud scenario you don’t know which physical server is running your virtual machine, which makes it impossible to link these licenses to particular physical servers. Actually Microsoft won’t allow you to use your own licenses in a public cloud scenario, you have to buy the licenses from your cloud provider under the SPLA (Service Provider License Agreement) model. This means your paying a license fee to your cloud provider and your using their agreement with Microsoft for your virtual machines.
Let’s see what Amazon Web Services (AWS) is telling us when licensing Windows servers running in their EC2 cloud:
Q. Can I use my existing Windows Server license with EC2?
No. Microsoft Windows Server licensing does not currently support using your existing Windows license in Amazon EC2 or any other cloud environment. We encourage you to work with your Microsoft account representative to understand licensing options.
Hmm, if I am not allowed to use my own licenses can I use my own images or do I have to use the images supplied by Amazon? If this is this case, this puts big limitations on the concept of workload mobility. Fortunately there’s some information about this on the AWS website:
When you import your on-premise Microsoft Windows VM images into Amazon EC2, AWS will provide the appropriate Microsoft Windows Server license key for your imported instance. Hourly EC2 instance charges cover the Microsoft Windows software and underlying hardware resources. Your on-premise Microsoft Windows license key will not be used by EC2 and you are free to reuse it for other Microsoft Windows VM images within your on-premise environment.
If you export an Amazon EC2 instance, access to the Microsoft Windows Server license key for that instance is no longer available through AWS. You will need to reactivate and specify a new license key for the exported VM image after it is launched in your on-premise virtualization platform.
So, yes you can move a workload but you’re required to change licensing key and use the Amazon supplied SPLA license key. The original becomes available and can be reused for another on-premises workload.
At this point you might think that Microsoft licensing is limiting these options from a competitive standpoint? Well, that’s certainly not the case. For Microsoft’s own Azure cloud a kind of the same statement is published:
If I upload my on-premises Windows Server image to Windows Azure, do I need to provide my license keys?
No. Microsoft provides the Windows Server license keys for any running instances.
If I download my Windows Server image running on Windows Azure to on-premises, is the license provided in Windows Azure transferrable to on-premises?
No. If you download your Windows Server image running on Windows Azure to on-premises, you will then be required to supply a license for the image.
I’ve been looking around to find more information on this for VMware vCloud IaaS providers, unfortunately I didn’t find a clear statement. I have found the following information in the VMware vCloud Hybrid Service Product FAQ:
Can I bring my existing virtual machines and licensed applications into vCloud Hybrid Service?
Absolutely. One of the key benefits of the hybrid cloud is the ability to bring your existing virtual machines and networking architecture into the hybrid cloud. In addition, the platform supports more than 3,700 applications from more than 2,200 technology partners.
vCloud Hybrid Service includes an operating system and application catalog as part of the service, which makes commonly used workloads available. As long as you maintain license compliance with your existing software vendor, you can bring your licensed software into the cloud without problems.
And that is exactly the caveat…(at least) Microsoft doesn’t support Cloud Mobility (that’s what it’s called) for the Windows Operating System; thus you’re not allowed to transfer your Windows OS license from private to public cloud.
Microsoft Server Applications and Workload Mobility
Although workload mobility is not available for the Windows OS, Microsoft supplies you with mobility options for some of their server applications a.i. Exchange, SQL Server and Sharepoint (the full list is on the Microsoft website). This means you’re allowed to install these selected applications on the SPLA license Windows OS in a public scenario (and transfer the license to the public cloud). Full details on the Cloud Mobility licensing option for applications is available on the Microsoft website: “License mobility through software assurance“. Software Assurance is key in this case and you have to take a few additional steps for compliancy. On top of this your Cloud Provider should be an Authorized License Mobility Partner and of course must be an SPLA.
I hope this article gave you some information on licensing Microsoft software in a cloud scenario. Always work with your Microsoft account representative to understand licensing options. This article is just based on information publicly available on the internet.