VCAP-DCD 5 – Section 2.1 – Create a vSphere Logical Design from an existing conceptual design 2.1

Objective 2.1 – Map Business Requirements to the Logical Design

  • Explain the common components of logical design
    • Logical design components include:
      • the relationship between all major infrastructure components
      • Conceptual design
      • Constraints and risks
      • Focuses on meeting the requirements
  • List the detailed steps that go into the makeup of a common logical design.
    1. Gather information from stakeholder interviews and current state analysis (documentation also)
    2. Define requirements:
      • Goals – Why, when
      • Scope – what, what not.
      • Assumptions – Already have
      • Constraints – don’t want or do want
      • Risks – What could stop plans
      • Functional requirements – what the system must/can do
      • Non functional requirements – how the system behaves
    3. Determine dependencies – What/who is affected by the project
    4. Create conceptual (napkin) design that achieves the goals and requirements and stays within constraints.
      • defines entities in the organisation and maps requirements/goals/constraints to each
      • Shows how the infrastructure (vsphere) capability addresses the requirement
      • Highest level design that addresses as many requirements as possible
      • Documented with block diagrams, tables and text.
    5. Seek and recieve approval for concept
    6. Create Logical (block diagram) design, it includes:
      • Arrangement of components and the relationship between each
      • Ensure constraints are considered
      • Highlights risks and mitigation to risks
      • takes capacity into account without detailing specific information. This could be associated with limits when a new cluster or vcenter is required.
      • Documented with a series of diagrams, tables and text.
  • Differentiate functional and non-functional requirements for the design
    • Functional requirements – A function that the system must be able to perform
      • Specifies specific functionality
      • Admin functions
      • business rules
      • Authentication
    • Non Functional requirements – specifies how the system should behave
      • specifies criteria that judge system operation – quality characteristics
      • Performance
      • Scalability
      • Capacity
  • Build non-functional requirements into a specific logical design
    • Design with non-functional requirements in mind. Examples are virtual machines with network connections at different levels of trust must not be hosted in the same Host. This will require only one vlan used in a host or cluster and where another is required a seperate host is used.
    • In the design below Shared storage is required to apply vSphere HA for specific workloads. The non-functional requirement is to make the workload highly available.
    • Other non-function requirements – allow the infrastructure to grow as the virtual machine workloads increase could require shared storage and DRS to be implemented.

  •  Translate given business requirements and the current state of a customer environment into a logical design
    • Business goals may be to virtualize existing appliations, provide VDI to replace old desktops and allow for expansion as business expands.
    • This will require a logical design showing vSphere management, Shared Storage and Cluster for VDI (cluster to allow for expansion of CPU and memory in future).
  • Create a service Catalog
    • A Service Catalog is a list of services that the IT entity (can be a company or part of a company) provide to its customers (can be another company or another part of a company). The Catalog should provide the following information:
      • Service name – e.g. Development testing
      • Service Description – e.g. Allow for software development to be tested so that latest builds are placed in templates and used in fenced networks when needed for developer testing.
      • Services included – e.g. Patch management, anti-virus, incident support, storage management, upgrades, documentation
      • Services not included – e.g. creation of virtual machines for testing and creation of templates
      • Services availability – e.g. 7am to 7pm mon to friday
  • ITILv3 Notes:
    • ITIL ensures that IT services align to meet business needs.
    • ITIL has 5 core areas:
      • Service Strategy: Service level package. Customers don’t buy products they buy the satisfation of particular needs.
        • Perspective – What is the vision for the service, Position – How will the service be positioned, Plan – How the vision ir to be achieved, Pattern – how things are done.
      • Service Design: Service Design package. Design IT services (includes architecture, processes, policies and documentation) to meet business requirements.
        • People – Skills and competencies for provisioning, Products – technology and systems to deliver the services, Processes – processes roles and activities involved in provisioning, Partners – vendors manufacturers and suppliers used to assist and support provisioning.
        • Service cataloge Management, Service Level Management, Capacity management, Availability Management, Continuity management and Security Managment.
      • Service Transition: Delivers the services required by the business into operational use.
        • Change Management, Configuration Management, Knowledge Management and Validation and testing.
      • Service Operation: To Deliver agreed levels of service to users and customers.
        • Key activities: Incident management, event management, access management and problem management
        • Key functions: Service desk management, application management, technical management and IT operations management 
      • Continual Service Improvement: maintains value to customers through evaluation and improvment to services.
        • Continual service improvement model:
          • What is the vision – Business vision, mission, goals and objectives
          • Where are we now – Baseline assessment
          • Where do we want to be – Measurable targets
          • How do we get there – Service and process improvements
          • Did we get there – Measurements and metrics
        • 7-step improvement process
          1. Define what you should measure
          2. Define what you can measure
          3. Gather the data – Quality is the key objective.
          4. Process the data
          5. Analyze the data
          6. Present and use the information
          7. Implement corrective action
        • Service Measurement
          • validate previous decisions
          • direct activities to meet targets
          • justify that action is required
          • intervene at the appropriate point
        • Service Reporting – Build actionable reports. What happened, what IT did, how IT will ensure it doesn’t happen again, any improvements.