This post is intended to cover the VCAP design objective around mapping business requires to a vSphere 6.x logical design. At the time of writing, the required ‘Skills and Abilities’ listed by VMware for this topic are:
- Analyze requirements for functional and non-functional elements
- Build non-functional requirements into a specific logical design
- Translate stated business requirements into a logical design
- Incorporate the current state of a customer environment into a logical design
I’ll look at each in turn in this post, starting with analyzing requirements for functional and non-functional elements.
Analyze requirements for functional and non-functional elements
I covered functional and non-functional requirements, when covering the previous objective around determining risks, requirements, constraints and assumptions when planning a design. This objective is about analyzing the requirements that have been determined, and building them into the design. A simple example of a requirement would be that ‘The design should avoid any single point of failure’. Whilst this example is a little vague and will likely need follow up questions with the relevant stakeholders, it is an extremely common requirement, and will influence many design decisions.
We need to look at the known requirements for the design and determine whether they are functional or non-functional requirements. As stated here, a functional requirement is about what the designed solution must do, whilst a non-functional requirement is about how it does it. Some examples could be:
[table id=2 /]
Build functional and non-functional requirements into a logical design
With the requirements determined to be functional or non-functional we can start to look at translating these into the logical design. For example, taking the last item in the table above, we can address the requirement for virtual machines to automatically recover from a host failure by including shared storage and vSphere HA in our design.
Remember, when doing the exam (and in real life!), a requirement is something that must be adhered to, and so each requirement identified needs to be addressed in the logical design.
Incorporate the current state of a customer environment into a logical design
This is about understanding the current environment and incorporating it into the logical design. An example here could be relating to the existing network configuration – for example, there may already be standards in place such as dedicated VLANs for management traffic or for certain types of workload, and it may be a requirement to adhere to the current network standards/design.
There may also be elements of the current environment that we need to make use of as part of the design, for example an existing NTP or syslog server.
Useful Links and Resources
VMware suggest a number of resources to refer to for this objective. These are:
Conceptual, Logical, Physical: It is Simple
What’s New in VMware vSphere 6.0
Functional vs. Non-Functional Requirements
ITIL v3 Introduction and Overview
Conceptual Architecture Action Guide
Systems Architecture Fundamentals – Conceptual, Logical, Physical Designs