Tag Archives: VCAP5-DCD

VDCD510 Objective 2.6 – Build Recoverability Requirements into the Logical Design

RTO & RPO
During the business continuity plan creation it is necessary to define the key metrics of recovery point objective (RPO) and recovery time objective (RTO). These two terms are used to define how fast a backup can be restored and the amount of data loss.

Recovery Time Objective (RTO): The time it takes to recover from a data loss event. This is the amount of time while the systems or service is unavailable.

Recovery Point Objective (RPO): The amount of time between backups. Leads to the possible amount of data loss.

Disaster Recovery and Business Continuity

Disaster recovery refers to previously defined steps taken by administrators to resume services or systems after a disaster event.

Business continuity is a high level overview of processes to ensure that an organization can resume their business after a disaster.

VMware offers a great free course about this topic: DRBC Design - Disaster Recovery and Business Continuity Fundamentals

VCAP5-DCD Exam Blueprint v1.1

Knowledge

  • Understand what recoverability services are provided by VMware solutions.
  • Identify and differentiate infrastructure qualities (Availability, Manageability, Performance, Recoverability, Security)
  • Differentiate Business Continuity and Disaster Recovery concepts.
  • Describe and differentiate between RTO and RPO

Skills and Abilities

  • Given specific RTO and RPO requirements, build these requirements into the logical design.
  • Given recoverability requirements, identify the services that will be impacted and provide a recovery plan for impacted services.
  • Given specific regulatory compliance requirements, build these requirements into the logical design.
  • Based on customer requirements, identify applicable site failure / site recovery use cases.
  • Determine recoverability component of SLAs and service level management processes.
  • Based on customer requirements, create a data retention policy.

Tools

Back to VCAP5-DCD Study Guide

VDCD510 Objective 2.5 – Build Performance Requirements into the Logical Design

Identify Infrastructure Qualities
We have already covered infrastructure qualities in objective 2.3. To recall them, here is a short overview:

Availability is the ability of a system or service to perform its required function when required. It is usually calculated as a percentage like 99,9%.
Manageability describes the expense of running the system. If you have a huge platform that is managed by a tiny team the operational costs are very low.
Performance is the measure of what is delivered by a system. This accomplishment is usually measured against known standards of speed completeness and speed.
Recoverability describes the ability to return a system or service to a working state. This is usually required after a system failure and repair.
Security is the process of ensuring that services are used in an appropriate way.

 

Key Performance Indicators
According to ITIL, a Key Performance Indicator (KPI) is used to assess if a defined service is running according to expectations. The exact definition of the KPIs differs depending on the area. This objective is about server performance which is typically assessed using the following KPIs: Processor, Memory, Disk, and Network. VMware offers several concepts for managing resources.

Processor
To manage CPU resources VMware relies on the the CPU scheduler. The CPU scheduler shares the same logical processor among multiple virtual machines. It defines the following terms:

  • Processor Socket: A physical CPU
  • Core: A logical core within a physical CPU
  • Logical Processor: A hyperthreading CPU Core presents itself as multiple logical processors

Memory
VMware offers the following features to manage the memory efficiently

  • Transparent Page Sharing: Shares identical Memory Pages among multiple virtual machines. This feature is active by default and does not impact the performance of the virtual machine.
  • Ballooning: Controls a balloon driver which is running inside each virtual machine. When the physical host runs out of memory it instructs the driver to inflate by allocating inactive physical pages. The ESX host can uses these pages to fulfill the demand from other virtual machines.
  • Memory Compression: Prior to swap memory pages out to physical disks the ESX server starts to compress pages. Compared to swapping, compression can improve the overall performance in an memory overcommitment scenario.
  • Swapping: As the last choice the ESX hypervisor starts to swap pages out to physical disks. This is definitely a bad situation as disk are much slower than memory.

Disk
Storage I/O Control (SIOC) allows cluster wide control of disk resources. The main goal is to prevent a single VM to use all available disk performance from a shared storage. With SIOC a virtual machine can be assigned a priority when contention arises on a defined datastore.

Network
Network I/O Control (NetIOC) enables traffic prioritization by partitioning of network bandwidth among the entire cluster.

 

VCAP5-DCD Exam Blueprint v1.1

Knowledge

  • Understand what logical performance services are provided by VMware solutions.
  • Identify and differentiate infrastructure qualities (Availability, Manageability, Performance, Recoverability, Security)
  • List the key performance indicators for resource utilization.

Skills and Abilities

  • Analyze current performance, identify and address gaps when building the logical design.
  • Using a conceptual design, create a logical design that meets performance requirements.
  • Identify performance-related functional requirements based on given non-functional requirements and service dependencies.
  • Define capacity management practices and create a capacity plan.
  • Incorporate scalability requirements into the logical design.
  • Determine performance component of SLAs and service level management processes.

Tools

Back to VCAP5-DCD Study Guide

VDCD510 Objective 2.4 – Build Manageability Requirements into the Logical Design

Identify Infrastructure Qualities
We have already covered infrastructure qualities in objective 2.3. To recall them, here is a short overview:

Availability is the ability of a system or service to perform its required function when required. It is usually calculated as a percentage like 99,9%.
Manageability describes the expense of running the system. If you have a huge platform that is managed by a tiny team the operational costs are very low.
Performance is the measure of what is delivered by a system. This accomplishment is usually measured against known standards of speed completeness and speed.
Recoverability describes the ability to return a system or service to a working state. This is usually required after a system failure and repair.
Security is the process of ensuring that services are used in an appropriate way.

Event, Incident and Problem Management
This concept is related to the well known ITIL standard.

Event: A change of state which might have an influence for the management of a service or system
Incident: An event which is not part of the standard operation. It might cause a service disruption or reduce the productivity.
Problem: The cause of one or more incidents. Problems are usually identified because of multiple incidents.

Please note that an incident might give a hint to the investigation of a Problem, but never become a Problem. Even if the incident is elevated to the 2nd level, it remains an incident. The problem management might manage the resolution of the incident when the incident can only be closed by solving the Problem.

Change Management
The change management process is responsible for controlling the lifecycle of all changes. Changes are defined as the addition, modification or removal of anything that could have an effect to services or systems. The primary objective of change management is to enable beneficial changes to be made, with minimum disruption.

VCAP5-DCD Exam Blueprint v1.1

Knowledge

  • KnowledgeUnderstand what management services are provided by VMware solutions.
  • Identify and differentiate infrastructure qualities (Availability, Manageability, Performance, Recoverability, Security)

Skills and Abilities

  • Build interfaces to existing operations practices into the logical design
  • Address identified operational readiness deficiencies
  • Define Event, Incident and Problem Management practices
  • Define Release Management practices
  • Determine Request Fulfillment processes
  • Design Service Asset and Configuration Management (CMDB) systems
  • Define Change Management processes
  • Based on customer requirements, identify required reporting assets and processes

Tools

Back to VCAP5-DCD Study Guide

VDCD510 Objective 2.3 – Build Availability Requirements into the Logical Design

Identify Infrastructure Qualities
VMware named five infrastructure qualities: Availability, Manageability, Performance, Recoverability and Security. If you are familiar with other design methodologies you might have encountered other terms, but here i want to describe the VMware terms.

Availability is the ability of a system or service to perform its required function when required. It is usually calculated as a percentage like 99,9%.

Manageability describes the expense of running the system. If you have a huge platform that is managed by a tiny team the operational costs are very low.

Performance is the measure of what is delivered by a system. This accomplishment is usually measured against known standards of speed completeness and speed.

Recoverability describes the ability to return a system or service to a working state. This is usually required after a system failure and repair.

Security is the process of ensuring that services are used in an appropriate way.

Lets take a website for example. To understand how to compare your design against this requirements you could ask yourself:

  • Availability: Is website up and running?
  • Manageability: How expensive is it to keep the system up?
  • Performance: How fast does the webserver responds?
  • Recoverability: If the server crashes, how fast can it be restored?
  • Security: Are the customers data safe?

Redundancy and Single Point of Failure
A single point of failure is a component of a system that, if it fails, will cause the entire system to fail. Systems can be made robust bei adding redundancy. A server usually attains internal component redundancy by having multiple hard drives, network connections or power supplies. By having multiple servers attached to a cluster you can archieve server hardware redundancy.

VMware Availability Services
vSphere High Availability (HA)
minimizes your downtime by restarting virtual machines on remaining hosts in case of hardware failures.

vSphere Fault Tolerance (FT) provides continuous availability for virtual machines by creating a live copy of a virtual machine to another physical host.

Differentiate Business Continuity and Disaster Recovery
Business Continuity is focused on avoiding or mitigateing the impact of a risk. (Proactive)
Disaster Recovery is focused on how to restore the services after a outage occurs. (Reactive)

VMware offers a course about disaster recovery and business continuity. It is free at the moment, so check it out:
DRBC Design - Disaster Recovery and Business Continuity Fundamentals

VCAP5-DCD Exam Blueprint v1.1

Knowledge

  • Understand what logical availability services are provided by VMware solutions.
  • Identify and differentiate infrastructure qualities (Availability, Manageability, Performance, Recoverability, Security)
  • Describe the concept of redundancy and the risks associated with single points of failure.
  • Differentiate Business Continuity and Disaster Recovery concepts.

Skills and Abilities

  • Determine availability component of service level agreements (SLAs) and service level management processes.
  • Explain availability solutions for a logical design based on customer requirements.
  • Define an availability plan, including maintenance processes.
  • Prioritize each service in the Service Catalog according to availability requirements.
  • Balance availability requirements with other infrastructure qualities

Tools

Back to VCAP5-DCD Study Guide

VDCD510 Objective 2.2 – Map Service Dependencies

This objective talks about service dependencies in your design and how to document them. Services could be everything that matters the design, DNS, databases or NTP for example. I will not go deeper into these services, instead of this I will explain the terminology.

Application Dependency Diagram
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

If you have a website for example. The website runs on a webserver which runs on a linux server which is hosted by a VMware Cluster. This is an example of the dependency map:

Upstream and Downstream Relationships
Everything that happens downstream can have an effect on upstream items. For example, if the webserver crashes, the website upstream is affected and goes down. Neither the operating system, nor the cluster are affected, as this are downstream relationships. To memorize this, you could think of a house. The roof is “up” while basement is “down”. If you break down the basement, the roof upstream” also collapses.

VMware offers a product called VMware vCenter Application Discovery Manager which can assist to discover and draw down these relationships.

VCAP5-DCD Exam Blueprint v1.1

Knowledge

  • Identify basic service dependencies for infrastructure and application services.

Skills and Abilities

  • Document service relationships and dependencies (Entity Relationship Diagrams)
  • Identify interfaces to existing business processes and define new business processes
  • Given a scenario, identify logical components that have dependencies on certain services.
  • Include service dependencies in a vSphere 5 logical design.
  • Analyze services to identify upstream and downstream service dependencies.
  • Having navigated logical components and their interdependencies, make decisions based upon all service relationships.

Tools

VDCD510 Objective 2.1 – Map Business Requirements to the Logical Design

The second objective talks about the logical design. When we talk about the logical design at this point in the project phase we are talking about a lower level design, compared to the conceptual design. If you take a network diagram for example, this is usually also a logical design but it contains much more information. Information you do not have at this point. So the purpose of a logical design is to dig deeper into the conceptual design and evaluate the design without getting lost in explicit connection or configuration details.

It is often not easy to understand the difference between physical, logical and conceptual design. To understand the difference, always remember the timeline. First you create a concept, something like “The customer wants to have a protected cluster with physically separated hardware”. The conceptual design is always the part the customer wants. The second step is the logical design. This is where the designer creates his logical design to fulfill the given requirements. This design should sound like “To fit the needs we need servers, connected to switches, connected to our storage.” Does the designer care about IP addresses, hostnames or hardware vendors at this point? No!

What should be shown in the logical design? Here are a couple of questions which might be part of the logical design:

  • Should the Cluster use HA and DRS?
  • Is Storage DRS a valid solution?
  • Does the customer need storage tiering?
  • Could Site Recovery Manager fit the needs?

If you are looking at a logical design you should usually see ESX hosts, physical switches, virtual switches, storages and the depencies between all components. Another hint: If the logical design is reusable at another customer without modification, it is a valid logical design.

Service Catalog
A new part in this objective and derived from ITIL is the service catalog. A service catalog is a list of services that a company provides to its customers. The catalog should provide the following information:

  • Service name (Extended Support)
  • Service description (Maintenance and support of servers and components)
  • Services included (Patch management, upgrades, incident support)
  • Services not included (Non-standard changes)
  • Services availability  (24x7x365)

VCAP5-DCD Exam Blueprint v1.1

Knowledge

  • Explain the common components of logical design.
  • List the detailed steps that go into the makeup of a common logical design.
  • Differentiate functional and non-functional requirements for the design.

Skills and Abilities

  • Build non-functional requirements into a specific logical design.
  • Translate given business requirements and the current state of a customer environment into a logical design.
  • Create a Service Catalog

Tools

VDCD510 Objective 1.3 – Determine Risks, Constraints, and Assumptions

This are very common project parts which are not related to VMware or virtualisation. If you are familar with project management this terms should be known.

Requirement
Requirements are the things that the project must achieve. This could be business or technical requirements. They are the detailed view of the Objectives the Project must deliver. Only a clearly defined list can avoid ambiguities durin the design process. The characteristics of good requirements are: verifiable, traceable, feasible, specific and unambiguous.

  • Must comply with ISO standards
  • The service uptime must be at a minumum of 99,9%
  • Users must be able deploy new virtual machine

Assumption
Assumptions are factors considered to be true without proof in the planning phase.

  • Equipment will be available at a certain date
  • The organisation has sufficent network bandwidth
  • Stakeholders will make a decistion in the next meeting
  • Server hardware has to be separated between dmz and internal servers

Constraint
Constraints could be a business policy or a technical limitation that is limiting the design choice.

  • The project has to be finished in 4 month
  • The total cost must not exceed $500.000
  • The hardware vendor has to been xxx

Risk
Risks might prevent achieving the project goals. They are a common point within every project as anything can happen during the project. Clearly identify and list every risk that might prevent further progress.

  • User commitment could be a problem in every project
  • Single point of failures in the existing environment
  • The most common risk is that the project being delivered late

VCAP5-DCD Exam Blueprint v1.1

Skills and Abilities

  • Differentiate between the general concepts of a risk, a requirement, a constraint, and an assumption.
  • Given a statement, determine whether it is a risk, requirement, a constraint, or an assumption.
  • Analyze impact of VMware best practices to identified risks, constraints, and assumptions.

Tools

VDCD510 Objective 1.2 – Gather and analyze application requirements

This section is really much about best practices and use cases. VMware offers a bunch of documents which are a little bit overkill for the exam, and to complex to memorize. So my advice for the exam is to skim through the documents and memorize the basics. If you have a real world project, this is also a great ressource to gather deep knowledge. The purpose of this section is to give a brief technical overview. Please refer to the resource in the Tools section for more details. A registration is required to download the application kits, but it's free.

The requirements should be documented in the same way as the business requirements.

VCAP5-DCD Exam Blueprint v1.1

Skills and Abilities

  • Given a scenario, gather and analyze application requirements
  • Given a set of applications within a physical environment, determine the requirements for virtualization.
  • Gather information needed in order to identify application dependencies.
  • Given one or more application requirements, determine the impact of the requirements on the design.

Tools

VDCD510 Objective 1.1 – Gather and analyze business requirements

Five-Step design process

  1. Initial design meeting
  2. Current-state analysis
  3. Stakeholder and SME training
  4. Design sessions
  5. Design deliverables

Project participants (SMEs / Key Stakeholders)
A design project manager has to determine a list of SMEs and project stakeholders who can provide information about the design requirements. This list typically includes:

  • Network administrators
  • Storage administrators
  • Server hardware administrators
  • Operating system administrators
  • Application administrators
  • Security Officer
  • HR representatives
  • C-Level executives (CEO, CTO, CIO,...)
  • Representatives

It is important to lists the people involved in this project and their contact information. This list should include:

  • Name
  • Title
  • Organisation
  • E-Mail address
  • Phone number
  • Reachability

Having contact information available will help to make progress without unnecessary interruption during the design process.

Stakeholder = A person with an interest in a project
SME = A subject-matter expert is a person who is an expert in a particular area.#

Functional / Non-functional requirements
Functional requirements are tasks or processes that must be performed by the system. For example, a functional requirement of a vSphere platform is "must allow multi tenancy" or "users must be able to create virtual machines".

Non-functional requirements are standards that the system under must have or comply with. For example, a non-functional requirements for a vSphere platform is "must be built for a total cost of $500.000". Non-Functional requirements are also called constraints.

Conceptual design
The conceptual design typically focuses on the business requirements. It is an high level overview which includes only the most important components. Concept design is the first phase of the design process.

Conceptual design from an stretched Cluster

Conceptual design from a webservices platform

Logical design
The logical design specifies the relationship between all components. It is usually stable which means that it will only change if the requierement changes. The logical design does not include physical details such as IP addresses, hostnames or hardware models.

Physical design
The physical design is usually the last and the most specific design. It shows port connections, IP addresses and model description.

Requirement tracking
It is important to document all requirements. This could be done in an excel sheet for example. Every single requirement should contain at least a unique number, desciption, timestap, priority and the originator.


VCAP5-DCD Exam Blueprint v1.1

Skills and Abilities

  • Associate a stakeholder with the information that needs to be collected.
  • Utilize customer inventory and assessment data from a current environment to define a baseline state.
  • Analyze customer interview data to explicitly define customer objectives for a conceptual design.
  • Identify the need for and apply requirements tracking.
  • Given results of a requirements gathering survey, identify requirements for a conceptual design.
  • Categorize requirements by infrastructure qualities to prepare for logical design requirements.

Tools

VCAP5-DCD - What's new?

The new VMware Certified Advanced Professional 5 Datacenter Design (VCAP5-DCD / VDCD510) Certification is now live. There is much new stuff with vSphere 5, but also the design process has changed. I was pleasantly surprised that there is a much of ITIL standardization in the new exam. As i come from the cisco world, i am already familiar with ITIL and the PPDIOO methodology. So while studying for the old VDCD410 exam i was a little bit surprised at the new design methodology VMware uses. Now with the VDCD510 exam the design process ich much more like ITIL, i think this is a good idea.

As the old exam there are no course requirements. There only requirement is a VCP5 status. Until August 17, 2012  if you are currently holding a VCAP4-DCD there are no additional requiremnts. Pass the VCAP5-DCD and achieve both, VCP5 and VCAP5-DCD.

I have worked through the VDCD510 Exam Blueprint to find the differences between the old and the new exam. As this is not a technical exam and the blueprint has been completely rewritten, it is not trivial to compare both, but i tried to extract the new stuff out of the blueprint as best as i can.

Logical Design
All design processes are now much more ITIL related. So knowledge about creating a Service Catalog is now part of the exam.

Applications
The new exam now covers Exchange Version 2010 and a completely new product: Enterprise Java. VMware now offers much more ressources for application virtualization which can be found here.

Map Service Dependencies
Timekeeping is no longer part of the exam.

Build Manageability Requirements
Building manageability requirements is now much more complex. Make yourself familiar with Operational Readiness Assessment.

Physical Storage Design
Beside the ITIL methodology the most new stuff has come with the physical storage design. There are much new features like VASA, Storage Policies, Storage DRS, Storage Tiering and the new vSphere Storage Appliance.

Configuration Maximums
One of the most important part every VMware Architect shouild know are the Configuration Maximums. Of course, there are many changes in vSphere 5, so you should memorise the new Configuration Maximums.

Additional New Features

  • Auto Deploy
  • Deploying Anti-Virus Solutions (VMware vShield Endpoint)
  • vCenter Server Virtual Appliance