VCAP DCD Study – Home Lab Design Part 2


Section 2 – Create a vSphere Logical Design from an Existing Conceptual Design


Objective 2.1 –Map Business Requirements to the Logical Design

1.Explain the common components of logical design.

The Logical Design specifies the relationship between all components, the components of my lab design are quite straightforward and comprise of 2 wireless routers, a smart switch, 2 ESXi hosts, 1 NAS drive and some ethernet cabling.

2.List the detailed steps that go into the makeup of a common logical design.

The steps involve gathering the requirements and creating a logical diagram that visually displays what needs to be built to fulfill those requirements.

3. Differentiate functional and non-functional requirements for the design.

I  struggle with these concepts and the reference material in the blueprint doesn’t really help, it talks about heart rate and blood pressure !!!! I wish they would relate the material to the technology we are studying, it might just be the way that my brain works but I need things spelled out in black in white.  Hey VMware…give us some solid examples that we can compare to our every day working lives please.

The definition for a functional requirement specifies what the system should do: “A requirement specifies a function that a system or component must be able to perform”
Functional requirements specify specific behavior or functions, for example:

Functional Requirements

  • The lab environment must be securely accessible from external sources but only accessible to the administrator.
  • Authentication must be validated through Microsoft Active Directory and VMware SSO.
  • The Lab should be able to support at least a vCenter Server, MS SQL Express database, and active directory server and an Update Manager.
  • VLAN tagging must be available on the switching infrastructure to separate traffic types.

Non-Functional Requirements

  • The vCenter Server and Database need to have some redundancy within the cluster.
  • Costs must be kept below £1500.
  • There should be enough compute resource to cater for vCenter Server, MSSQL Express, AD and Update Manager.
  • The design must use and existing IOMEGA NAS device.
  • Hosts need to be patched on a regular basis and kept in a consistent configuration.
  • Space is at a premium so the physical footprint of the equipment needs to be a small as possible.
  • Power consumption needs to be low.


Skills and Abilities

4. Build non-functional requirements into a specific logical design.

Here’s a non-functional logical diagram depicting the use of the IOMEG NAS device.


5. Translate given business requirements and the current state of a customer environment into a logical design.

Logical Diagram to follow…..

6. Create a Service Catalog

A service catalog is introduced from ITIL and should contain the items below.

  • Service name

Home lab Support

  • Service description

Maintenance and support will be included for the following devices..

2 x HP Micro Servers with ESXi 5.5 installed

1 x Virgin SuperHub

1 x Asus RT-N66U Wireless Router

1 x TP-Link Smart Switch


  • Services included

Patch management


Incident support

  • Services not included

Tea and Coffee making

  • Services availability



Objective 2.2 – Map Service Dependencies

1. Identify basic service dependencies for infrastructure and application services.

As this is a green field site there is no need for application discovery and application mapping, if needed I can do this using VMware vCenter Application Discovery Manager.  For the purpose of the Exam blueprint below are the discovery methods.

  • Active – uses common network protocols to remotely query servers to build up an overall picture, it can put a burden on network resources and doesn’t give any relationship data. It doesn’t require agents.
  • Passive – provides more relationship data than the above active discovery, it listens and samples network traffic to see how network hosts and servers talk to each other and on what ports. Does require agents.
  • Analytics – complements the above 2 by performing deep packet analysis of observed traffic.

vCenter Server is dependent the MSSQL database and SSO

SSO is dependent on Active Directory

MSSQL is dependent on Active Directory as I’ll be using service accounts for the database.

Skills and Abilities
2. Document service relationships and dependencies (Entity Relationship Diagrams)

An application dependency diagram determines which entities are related with another. While discovering running services during the current state analysis you can use this information to draw down the upstream and downstream relationships. Relationships could be defined in the following terms:

  • runs on / runs
  • depends on / used by
  • contains / contained by
  • hosts / hosted by


3. Identify interfaces to existing business processes and define new business processes

Doesn’t really apply to this design but if in the real world during the discovery process if something was discovered that needed to be changed as part of the design and will impact the way the environment is to be managed, then the new process needs to be documented.

4. Given a scenario, identify logical components that have dependencies on certain services.

Covered this above.
5. Include service dependencies in a vSphere 5.x logical design.

Not really sure what to say about this, but I will be including the service dependencies in the logical design.

6. Analyze services to identify upstream and downstream service dependencies.

Everything that happens downstream can have an effect on upstream items. For example, if the SQL database crashes, the vCenter will stop. 

7. Having navigated logical components and their interdependencies, make decisions based upon all service relationships.

I’m assuming they are talking about grouping virtual machines together using VAPPs but I don’t plan to do this in my design.

So that’s the first 2 objectives of section 2 in the blue print addressed, objective 2.3 and onwards will be covered in the next post.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s