John Joyner begins a series that outlines the steps involved in building a private cloud based on a host-and-tenant model where central IT is the "cloud hoster" for its internal business units.
In the public cloud scenario, the IT department of a company (the tenant) is purchasing capacity from an outside service provider (the cloud hoster). This model applies to the modern IT department in the medium and large enterprise that treats its internal business units as tenants, or customers, of the central IT department. This scenario has implications for all organizations seeking the highest efficiencies in IT, which is to adopt the service-provider model.
There are four high-level steps to deliver this scenario using Microsoft System Center 2012 Service Pack 1 and Windows Server 2012. In this post, I will cover preparing the fabric resources in System Center Virtual Machine Manager. In three additional posts, I will cover these high-level steps:
- Build private cloud capacity and assign to cloud tenants using SCVMM
- Consume cloud resources (as tenant) using System Center App Controller
- Provide self-service cloud resources (as service provider) using Service Provider Foundation (SPF) and Windows Azure Services for Windows Server (WASWS)
Preparing the fabric resources in SCVMM
In this first article in the series, we will cover how to prepare the fabric in SCVMM. The fabric consists of the infrastructure that you need to manage and deploy hosts, and to create and deploy virtual machines and services to a private cloud. In this scenario, the fabric exists in the service provider data center. The fabric capacity will be consumed by the tenant, also known as the customer -- or the business unit.
Provision each business unit with a private cloud that has metered capacity-on-demand. Optionally extend delegated administration. Deploy System Center Operations Manager (SCOM) because this lets you produce charge-back reports in SCOM against clouds defined in SCVMM.
- The web site, storage, database, compute, and network resources consumed by each cloud can be metered and reported on in detail.
- Charge-back of data center fabric resource consumption is now visible on a per-cloud basis.
- Business unit leaders now have other dimensions of play within the enterprise, such as striving for the lowest cost, or most power saved, compared to other business units.
Configuring host groups
You first need to create a host group structure in SCVMM and configure host group properties. You use host groups to group virtual machine hosts, often based on physical site location and resource allocation. When you design a host group structure, consider that by default, child host groups inherit settings from the parent host group.When you create a private cloud, you select which host groups will be part of the private cloud. You can then allocate all or some of the resources from the selected host groups to the private cloud. Figure A shows the host group named TechRepublic with two hosts that are members of the host group.
The "TechRepublic" host group is created in SCVMM, with 2 hosts added
Configuring the library
The SCVMM library is a catalog of resources used to build the fabric, such as virtual hard disks, ISO images, scripts, driver files and many other building blocks for the dynamic data center. The SCVMM library also logically includes virtual machine (VM) and service templates and profiles (used to standardize the creation of virtual machines and services). These configurations are stored in the SCVMM database. Here are some considerations for library design:
- Equivalent objects are groups of library resources that you tell SCVMM to consider as the same object(s), that is, two or more copies of the same thing. With this feature, you can create data center automation processes that do not depend on particular physical resources-- achieving cloud-independent fault tolerance for the library objects customers will depend on for self-service to work.
- Private cloud libraries can have a node in SCVMM where self-service users who have appropriate permissions can store virtual machines and services. A delegated administrator can add resources to the read-only library shares that they want to make available to users of their private cloud.
To prepare the library for a tenant, make sure any resources needed by the tenant for self-service provisioning, such as .ISO files or VM templates, exist in the library such that they can be shared with the tenant when needed.
Configuring networkingAn SCVMM concept is network virtualization, which allows you to deploy multiple virtual networks on the same physical network. You can deploy switch extensions, such as quality of service (QoS) to let you control how your network bandwidth is used. Figure B shows the Fabric -> Networking -> Load Balancers node in the SCVMM console. Observe that a Citrix NetScaler virtual load balancer appliance has been added to the fabric.
Configuring networking can include virtual and physical load balancers.
Provisioning the networking for a tenant may require logical switches and potentially logical networks to be deployed. Services the tenant could purchase might include load balancers. Consider that a virtual load balancer appliance can cost much less than a dedicated hardware appliance and work just as well.
SCVMM can use local or remote storage for the automated creation and storage of virtual machines and resources. Local storage means direct attached storage (DAS) to the SCVMM computer. Remote storage means storage from an external storage device, with scaling and capacity provided by the storage provider.Remote storage includes traditional block-level storage-such as logical unit numbers (LUNs) for storage, using fiber channel, iSCSI, and SAS technologies; remote storage can also be file-based. Network shares that support the server message block (SMB) 3.0 protocol can reside on a Windows Server 2012 file server or on a network-attached storage (NAS) device from storage vendors such as EMC and NetApp. Figure C shows the three types of remote storage provider that can be added to the fabric.
Add remote storage: SMB remote file share, SMI-S SAN or NAS device, or SMP SAN device.
Storage resources to meet tenant requirements for scaling out must be available in the datacenter. A key concept is the service provider obligation to have a dynamic storage provider ready when tenant demands for capacity arrive. This may involve some planning and investment in Windows Server 2012 file servers and/or storage hardware with dynamic provisioning features like SMI-S or NAS SMB 3.0.More Information
For full details on the steps covered in this article, consult this link at Microsoft: