VCAP Storage Conceptual Model

What are Business Requirements?

The core goals, outcomes, and business drivers requested by stakeholders that the solution must support.

Why are Business Requirements important?

They define why the project exists and provide the basis for technical design decisions.

Give examples of Business Requirements.

Reduce deployment time, support multi-region availability, improve scalability, meet compliance requirements, or reduce operational costs.

What stakeholder concern is addressed by Business Requirements?

Desired business outcomes and organizational objectives.

What should every design decision map back to?

A documented business requirement.

What does RCAR stand for?

Requirements, Constraints, Assumptions, and Risks.

Why is the RCAR framework important?

It documents key design considerations and helps justify architecture decisions.

What is a Requirement in RCAR?

A statement describing what the solution must achieve.

What are functional requirements?

Requirements describing specific capabilities or services the solution must provide.

What are non-functional requirements?

Requirements defining quality attributes such as performance, availability, security, or scalability.

Give an example of a functional requirement.

The solution must support 5,000 virtual machines.

Give an example of a non-functional requirement.

The solution must maintain 99.99% uptime.

What is a Constraint in RCAR?

A fixed limitation or restriction that cannot be changed by the design team.

Why are constraints important?

They define the boundaries within which the solution must be designed.

Give examples of constraints.

Fixed budget, existing hardware requirements, compliance regulations, licensing restrictions, or datacenter space limitations.

Can architects change constraints?

No. Constraints must be accommodated within the design.

What is an Assumption in RCAR?

A condition accepted as true without complete verification during the design phase.

Why are assumptions documented?

To identify dependencies that may require later validation.

Give an example of an infrastructure assumption.

The network team will provide 10GbE connectivity before deployment.

What risk is associated with assumptions?

If an assumption is incorrect, the design may require changes or remediation.

What is a Risk in RCAR?

A potential event that may negatively affect project success.

Why identify risks early?

To allow mitigation planning before issues occur.

Give an example of a project risk.

A storage vendor may not deliver hardware before the deployment deadline.

What should accompany every identified risk?

A mitigation strategy or contingency plan.

Which RCAR component describes what the solution must achieve?

Requirements.

Which RCAR component describes fixed limitations?

Constraints.

Which RCAR component describes expected conditions not yet verified?

Assumptions.

Which RCAR component describes potential future problems?

Risks.

What does AMPRS stand for?

Availability, Manageability, Performance, Recoverability, and Security.

What is the purpose of AMPRS?

To evaluate and document key design quality attributes.

What is Availability in AMPRS?

The ability of a system to remain operational and accessible.

How is availability commonly measured?

Uptime percentage or service-level agreements (SLAs).

What design features improve availability?

Redundancy, clustering, load balancing, and fault tolerance.

Give an example of an availability requirement.

The solution must provide 99.99% uptime.

What is Manageability in AMPRS?

The ease of operating, monitoring, maintaining, and supporting the environment.

Why is manageability important?

It reduces administrative effort and operational complexity.

What design characteristics improve manageability?

Automation, centralized management, monitoring, and standardization.

Give an example of a manageability requirement.

Administrators must manage all clusters from a single interface.

What is Performance in AMPRS?

The ability of the solution to meet latency, throughput, and responsiveness requirements.

How is storage performance commonly measured?

IOPS, throughput, and latency.

How is compute performance commonly measured?

CPU utilization, response time, and workload capacity.

Give an example of a performance requirement.

Database storage latency must remain below 5 ms.

What is Recoverability in AMPRS?

The ability to restore services and data after a failure.

Which metrics are commonly associated with recoverability?

RPO and RTO.

What does RPO stand for?

Recovery Point Objective.

What does RPO measure?

The maximum acceptable amount of data loss.

What does RTO stand for?

Recovery Time Objective.

What does RTO measure?

The maximum acceptable service restoration time.

Which technologies support recoverability?

Backups, replication, snapshots, and disaster recovery solutions.

Give an example of a recoverability requirement.

The environment must achieve a 15-minute RPO and 1-hour RTO.

What is Security in AMPRS?

The protection of systems, applications, and data from unauthorized access or threats.

Which design areas are included in security?

Authentication, authorization, encryption, auditing, and compliance.

Why should security be considered early in design?

Security requirements often affect architecture, operations, and compliance decisions.

Give an example of a security requirement.

All sensitive data must be encrypted at rest and in transit.

Which AMPRS category relates to uptime?

Availability.

Which AMPRS category focuses on operational simplicity?

Manageability.

Which AMPRS category focuses on latency and throughput?

Performance.

Which AMPRS category focuses on backups and disaster recovery?

Recoverability.

Which AMPRS category focuses on protecting data and systems?

Security.

What is the relationship between RCAR and AMPRS?

RCAR identifies design inputs and constraints, while AMPRS evaluates the quality of the resulting solution.

Which framework helps identify stakeholder requirements and project assumptions?

RCAR.

Which framework is used to validate architecture quality attributes?

AMPRS.

When documenting a design, what should requirements map to?

Business requirements and stakeholder objectives.

Which is more difficult to change: a requirement or a constraint?

A constraint because it represents a fixed limitation.

True or False: Assumptions should be validated during the project lifecycle.

True.

True or False: Every risk should have a mitigation strategy.

True.

True or False: Availability and Recoverability are the same thing.

False. Availability focuses on keeping services running, while Recoverability focuses on restoring services after failure.

What is a tradeoff between Availability and Cost?

Higher availability typically requires additional hardware, redundancy, and operational expense.

What is a tradeoff between Performance and Cost?

Higher performance generally requires more powerful hardware and increased investment.

What is a tradeoff between Security and Manageability?

Additional security controls may increase administrative complexity.

What is a tradeoff between Availability and Manageability?

Highly available solutions may be more complex to manage.

What should drive all infrastructure design decisions?

Documented business requirements.

What is the first step of good architecture design?

Understand the business requirements and stakeholder objectives.