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Reference Architecture for Private Cloud
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There may be scenarios that span multiple categories such as regulatory and compliance requirements that place demands on each of the areas however when completing a Infrastructure as a Service design those scenarios that span categories may be refactored
by the architect into unique scenario drivers appropriate to each category.
The fabric of a private cloud consists of physical resources that include servers, storage and networking that collectively compose the Infrastructure Layer. These resources along with supporting facilities such as power infrastructure, cooling plants, and
building environmental controls also must be considered in the overall fabric management design.
Taking a closer look at each of these resources we find that server resources fall into several roles. These are:
Similarly the storage and networking resources are provisioned to support the servers in each of the roles.
In traditional IT servers may have been racked and cabled into an enterprise storage and network infrastructure. The software components would be installed either manually or published through software deployment technologies and tools. Eventually a large part
of the overall deployment may be scripted providing a degree of repeatability and automation. As the industry and enterprise progressed into highly Virtualized
Infrastructure environments the need to create the host infrastructure still exists and many scripted processes move forward and integrated into virtual machine image authoring. As hardware platforms progressed from standalone servers to blade configurations
with integrated communications hardware greater automation of the environment could be realized.
The Private Cloud Reference Architecture defines several Principles,
Patterns, and Concepts that provide A Perception of Infinite Capacity and Continuous
Service Availability while Optimizing Resource Usage with
Minimal Human Involvement. This can only be achieved in a highly virtualized environment with end-to-end service management automation and orchestration.
Automation and Orchestration is covered in the article Private Cloud Infrastructure as a Service Automation and Orchestration.
In the previous section we discussed the need for Automation and Orchestration to enable the desired characteristics of a private cloud. Before we perform automation we first must understand a wide range of concepts including what we are automating, how
communication is performed between elements of the infrastructure, the events posted by the infrastructure, where events are posted and the available management interfaces to act on the infrastructure.
The Private Cloud Reference Architecture defines some key principles to be considered in designing fabric management. These are:
Fabric Management involves encoding the desired aspects into a service template. These service templates are used to automate the overall deployment, operation and monitoring of the services that are hosted in a private cloud. This fabric management typically
also includes the monitoring of the management layer and facilities.
Fabric Management is covered in the article Private Cloud Infrastructure as a Service Fabric Management.
Self Service capability is a characteristic of private cloud computing and must be present in any implementation. The intent is to permit users access to a self-service capability and be presented with options available for provisioning in an organization.
The capability may be basic where only provisioning of virtual machine with a pre-defined configuration or may be more advanced allowing configuration options to the base configuration and leading up to a platform capability or service.
Self service capability is a critical business driver that enables members of an organization to become more agile in responding to business needs with IT capabilities to meet those needs in a manner that aligns and conforms with internal business IT requirements
This means the interface between IT and the business are abstracted to simple, well defined and approved set of service options that are presented as a menu in a portal or available from the command line. The business selects these services from the catalog,
begins the provisioning process and notified upon completions, the business is then only charged for what they actually use.
This is analogous to capability available on Public Cloud platform. See Private Cloud Infrastructure as a Service Self Service.
Infrastructure as a Service as the name implies refers to providing IT computing infrastructure capabilities in a service oriented manner. Therefor in the context of Infrastructure as a Service the service is the set of capabilities provided by the IT organization
that are governed by proven practices and monitoring throughout the lifecycle of the service. There are two perspectives to Infrastructure as a Service, the consumer perspective and the service provider perspective. Each perspective has their perception and
expectation about how the service should perform and be delivered. These expectations are clearly defined in a mutual exchange between the provider and consumer and take the form of a service contract. Meeting the requirements of the service contract for both
the consumer and providers perspectives and referred to as Service Management.
Service Management seeks to balance the expectations of the consumer of IT services with the expectations of the IT organization to deliver those services in a repeatable, secure and reliable manner consistent with industry best practices and business compliance
The Service Management processes and tooling guide us in defining the problem domain for Private Cloud Infrastructure as a Service. The Service Management processes are illustrated in the Private
Cloud Reference Model along two layers: The Service Operations and Service Delivery Layers. Both of these layers represent business or operational processes that define requirements that the Management Layer must implement via staffing or systematically.
In a private cloud the goal must be to achieve a very high degree in automating management operations associated with delivering a service. This Service Management Automation becomes the essence of the Infrastructure as a Service Problem Domain Definition.
Business owners are seen as needing the ability to quickly respond to change in business need and find themselves looking for alternatives when resources or time constraints provided by IT are inadequate to meeting the need. Self Service is a common capability
of a private cloud and permits business owners consume IT resources that have been designed by IT to comply with business or regulatory requirements. Self Service enable business agility and control while manintaing IT compliance and monitoring.
This scenario can arise for one or more reasons including a traditional IT model of physical deployment of resources in a vertical or silo manner to meet the needs of each individual application or workload requirement. This can also result from a lack of
or underutilization of management and monitoring tools to properly access the utilization of enterprise resources and may be linked to the capability in the overall IT maturity model.
Cloud computing and specifically Infrastructure as a Service designs that utilize the Private Cloud Reference Model are designed using several principles
Taking a Service Providers Approach, this principle positions the business as customers of IT and IT as a service provider to the business. This relationship requires the IT organization to have a very high level of maturity. This maturity leads to a discipline
of understanding the business and trends over time so that accurate assessment of need occurs in time to meet it. This combined with the principle of Optimization
of Resource Usage lead to cost reduction and optimum utilization of resources though sharing of appropriate resources across the enterprise. This is commonly more accepted in private cloud deployments since all corporate data remains in-house. Hybrid private
clouds also benefit since the data that cannot be hosted also remains in-house.
The principle of Incentivize Desired Behavior also encourages consumers of IT resource to only use what they actually need.
And finally the fabric management requirements of a private cloud require that IT processes he highly automated and monitored providing the fabric and IT exposure to unutilized resources and an automated ability to re-provision workloads accordingly.
This is a continual ask and evolution of IT. The IT organization wishes to continually improve the ability to deliver IT in a consistent, secure and repeatable manner. The principle of Achieve
Business Value through Continued Measured Continual Improvement is core to every private cloud. Inherently private clouds today are likely deployed on current generation technology and using the latest fabric management tools to manage the infrastructure.
These tools provide powerful design and validation capabilities to enable the user to improve process and automation workflows as business and technology needs evolve.
This is also a common ask of IT to essentially do more with less staff. This is sometimes seen as a threat to IT however it should be seen as an opportunity for both IT and the business. A private cloud Infrastructure as a Service deployment is highly automated
therefore allowing IT staff to focus on process maturity improvement and authoring of new or additional capabilities on the private cloud. Those IT professionals that level up to possess instrumentation, scripting and automation skills necessary in a private
cloud environment benefit the overall maturity of the enterprise and value to the business.
Infrastructure as a Service is the foundation for supporting Platform as a Server and Software as a Service workloads deployed on a private, hosted or hybrid cloud. The same Management Fabric and associated process and discipline apply to workloads deployed
into higher layers of the private cloud.
IT Operations sees self-service as a means to enable a well-defined set of IT capabilities to business owners while maintaining the business or regulatory governance required to minimize risk to IT and the business. This also frees IT staff to focus on other
aspects of the business in addition to new opportunities.
has anyone seen an example of a large private cloud using hyper-v with vmm? The feature set is building towards charge-back and tenancy, but i have yet to really see an example of anyone pushing these systems past a handful of hosts and a couple hundred vms. Is there anyone actually using this product with 100's of hosts, thousands of vms in a production or even a tested environment?