Sunday, July 3, 2011

Understanding the Service-concept in VMM 2012

For those of you that have tested and played around with VMM 2012, may be aware of the new concept of services. VMM 2012 inherited the great possibility to create VM templates from VMM 2008 R2, and has taken this a bit further in 2012.

When you create a VM template in VMM 2012, you can define the following configuration:

·         Hardware Configuration (HW Profile)
·         OS Configuration (OS Profile)
·         Application Configuration (Application Profile)
·         SQL Server Configuration (SQL Profile)

It`s worth to pay attention to that if you`re touching the Roles/Features in the OS profile, or/and the Application Profile/SQL Profile, you will get a message when you deploy your VM, that it need to be deployed as a service, since it contains additional configuration (not only the HW profile with a reference to a vhd, networking, CPU`s, RAM, and the OS profile with admin password, domain information, time zone, and license key).
If you choose to continue, these options will be ignored.

So, let`s move over to the Service Templates.
In VMM 2012, you can create a service, which is a logical grouping of VMs that you can manage as a single entity.
You can either create a single-tier service, or a multi-tier service.

Explanations:
A single-tier service contains a VM with ‘additional’ configuration. Like Application configuration, OS roles and features, SQL deployment/DACPAC`s, web apps, and so on. You can create a single-tier service, and scale it out. We will come back to the scaling later in this article.
A multi-tier service contains more than one VM. For example, you can deploy one SQL server tier, one Server App-V tier, and two Web App tier. These VMs will together define the service, and be their own little ecosystem.

It`s worth to mention that some people think that the service deployment is suited for other types of deployments. You can, technically deploy your Domain Controller, Remote Desktop Server, VPN server, and whatever server you`d like through this feature, but that is not what it`s meant for, unless it`s all a part of an application on the top, which you intend to scale out. Let me try to explain.
With VMM 2012, you`re able to manage the lifecycle of your applications. But remember that each and every application has some sort of software dependencies, some sort of manual input and requirements. So the service deployment and ‘scale-out’ is not suited for every application.

You can add, sort, and manage the underlying hardware in the Fabric in VMM 2012. In these days, the word Fabric is the new term of ‘infrastructure’. VMM 2012 gives you the opportunity to create a Private Cloud, which is primarily an Infrastructure – as a Service offering. With the Service deployment-feature, you`re actually able to provide your users with Software as a Service. But I will stress again, the scale-out purpose is meant for stateless application. Talking about stateless applications, this is particularly well for applications distributed with Server App-V. You can save the state of the application and reapply that state to the “new” VM. The new drag-and-drop Service Template Designer makes it easy to visually position VMs that comprise a service. (BTW: When you scale-in a service in VMM 2012, you`re in fact – deleting the VM).

Next blog: Example of a scale-out scenario.

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