Not every VMware professional needs the skill set that will earn a VCDX, but thinking like a VCDX pays off for designs, upgrades, troubleshooting and daily operations.
About 120 people hold the VMware Certified Design Expert (VCDX) certification -- a small fraction of the VMware admins and architects using vSphere and vCloud. The VCDX tests a VMware architect or admin's knowledge of infrastructure design. John Arrasjid, Mostafa Khalil and Ben Lin -- VCDX #001, #002 and #045 respectively -- share how to approach your VMware architecture and operations like a VCDX.
Many VMware professionals double as architect and admin. Does working as an admin improve your skills as an architect and vice versa?
Mostafa Khalil: When architects start as admins, the experience informs their designs. If you change something in one part of an infrastructure, it can have a domino effect because of the dependencies between components.
Troubleshooting and exposure to good and bad setups will teach you safer and more productive design, and help you identify problems' root causes.
John Arrasjid: There's a feedback loop between admins, architects and support teams on issues in a design and in its implementation.
How does VMware infrastructure design affect operations?
Arrasjid: Focus on the business drivers for a design, not the technology options that are out there. The technology could be the best in the world, but not good for the use case. For example, if you have Hadoop clusters, you would not want to use fault tolerance. But for a critical business app, fault tolerance would be essential.
Khalil: And if that critical app requires more than one CPU, then you would not be able to use VMware Fault Tolerance to maintain its uptime. On paper, the design looks great, but it doesn't work.
Arrasjid: If you change the design slightly, it will save you a big workaround with the technologies. Best practices aren't gospel. At the VCDX level, you don't just follow a best practice. You see why it exists and ask, "Does that best practice apply here?"
Ben Lin: A VCDX candidate can be very technically adept, but without the architecture design skills and applicable experience to create a comprehensive design plan.
VCDX panel defense is very different than a real-world design meeting: It's timed, the reviewers are all VCDXs and only the candidate explains and defends design choices. But what VCDX defense principles should VMware professionals adopt for real-world design or upgrade planning?
Arrasjid, Khalil and Lin are co-authors of VCDX Boot Camp: Preparing for the VCDX Panel Defense, ISBN 978-0-321-91059-2, available courtesy of VMware Press, a publishing alliance between Pearson Education and VMware Inc. Read Chapter 2 on VCDX preparation here.
Lin: Prepare -- for VCDX or real-world meetings -- via mock defenses and other study groups. You need experience articulating a design in front of an audience. At VCDX panel defense, you must justify each decision just like you would to a customer. Don't feel antagonized by questions. Panelists, executives or customers just want more data points to help with their assessment.
Arrasjid: Have others review your [design] materials and pull out any areas for review. Be consistent with the same technologies throughout a design. If the design calls for active-active pathing, it can't switch to active-passive pathing halfway through.
Khalil: There's also the community to help; connect with VMware's current VCDXs.
Arrasjid: Real-world designs are usually split up among a team, with input from each member. Early in the design phase, you'd make changes over multiple meetings. The VCDX panel defense is akin to the final design meeting.
How can VMware architects adapt when product cycles are as rapid as less than one year between releases?
Khalil: Designs should include next steps and planning for future upgrades, but avoid dependencies on future changes in APIs. Third-party component changes are a risk.
You may need to modify or redesign the existing vSphere architecture for an upgrade. The architect must be familiar with the old and new technologies in play. A company could reuse its existing hardware with new software, making compatibility a business driver.
Arrasjid: Focus on the concept; that is not time-sensitive. Make technology choices late in the process to match product cycles. Join beta programs [for new products or major updates], read forums and check VMware's reference architectures, guidelines and best practices.