Eric Sloof

I am absolutely thrilled to share some fantastic news with you all! My session, "VMware Cloud Foundation Troubleshooting: Real-World Scenarios and Solutions", has been selected for the inaugural VMUG Connect Amsterdam, taking place from March 17-19, 2026, at the RAI Amsterdam.

It is an incredible honor to be chosen as a speaker for this new, flagship event. For years, the VMUG community has been a cornerstone of my professional journey, and having the opportunity to give back by sharing my experiences with VMware Cloud Foundation is something I am genuinely excited about.

Mark your calendars! My breakout session is scheduled for the final day of the event:

• Title: VMware Cloud Foundation Troubleshooting: Real-World Scenarios and Solutions
• Track: Solutions in Action
• Date: Thursday, March 19, 2026 - Amsterdam
• Time: 10:45 AM – 11:30 AM

• Time Slot: April 8, 4:15 PM - 5:00 PM - Minneapolis

As the official description states, this session is designed to go beyond theory and dive straight into the practical, real-world challenges we face in production environments. We will walk through common problems encountered with new deployments, upgrades, license management, and workload domains. My goal is to equip you with actionable, step-by-step solutions for troubleshooting VCF compute, storage, and networking components.

This session is based on my extensive experience in the field and the comprehensive VMware Cloud Foundation Troubleshooting course material. I plan to cover a wide range of topics to provide you with valuable, hands-on insights. You can expect to learn how to:

• Apply a structured troubleshooting methodology to resolve common VCF validation and precheck errors.
• Identify and use the correct log files to troubleshoot the VCF Installer and licensing components.
• Effectively troubleshoot network pool creation and ESX host commissioning.
• Monitor vSAN and network health using the VCF Operations console.
• Generate and review VCF support bundles to diagnose complex issues.

Whether you are a seasoned VCF administrator or just getting started, this session will provide you with practical techniques to enhance your troubleshooting skills and build confidence in managing your VCF environment.

For those who haven't heard, VMUG Connect is the exciting new multi-day format that replaces the traditional UserCons. It promises a more immersive experience with deeper technical content, more hands-on labs, and invaluable networking opportunities. Taking place over three days at the RAI Amsterdam, this is set to be the premier VMware community event in Europe for 2026.

It’s the perfect opportunity to connect with peers, meet industry experts, and get hands-on with the latest VMware innovations. I am incredibly excited about this new format and the chance to meet so many of you in person.

I truly hope to see you in Amsterdam in March. Please make sure to register for VMUG Connect and add my session to your schedule. I look forward to sharing my knowledge, learning from your experiences, and connecting with the amazing Dutch and international VMware community.

See you at the RAI!

In today's data-driven world, ensuring reliable and resilient access to applications and their data is no longer a luxury—it's a fundamental requirement for nearly all IT organizations. Virtualization has transformed the data center, and with it, storage has evolved. VMware vSAN stands at the forefront of this evolution, shifting the paradigm from traditional, siloed storage arrays to a powerful, software-defined storage solution integrated directly into the hypervisor.

This article explores the core availability technologies within VMware vSAN, with a special focus on the advancements introduced in the Express Storage Architecture (ESA). We will break down how vSAN ensures data remains available and resilient across a wide range of failure scenarios, from a single drive failure to an entire host outage. The insights shared here are based on VMware's official whitepaper, "vSAN Availability Technologies: Resilience Capabilities for vSAN in VMware Cloud Foundation 9.0", published in December 2025.

VMware vSAN is a distributed storage solution that aggregates local storage devices from a cluster of vSphere hosts to create a shared storage pool. This approach offers incredible scalability and flexibility. At a high level, vSAN comes in two flavors: the Original Storage Architecture (OSA) and the more advanced Express Storage Architecture (ESA), introduced in 2022.

According to the VMware whitepaper, ESA represents a significant leap forward in performance, efficiency, and resilience. Unlike OSA, which utilized disk groups with a mix of caching and capacity devices, ESA employs a single tier of high-performance NVMe devices. This streamlined design minimizes the impact of a hardware failure, dramatically reducing the time it takes to restore data to its prescribed level of resilience.

To illustrate the difference, consider the impact of a single storage device failure as documented in the whitepaper:

This table clearly shows that ESA's architecture provides a much smaller failure domain, leading to faster recovery and better overall performance during degraded states.

vSAN manages data in the form of objects, which are the primary units of storage that make up a virtual machine, such as its virtual disks (VMDKs) and configuration files. As described in the VMware documentation, these objects can be up to 62TB in size and are broken down into smaller components. The placement of these components across the hosts in the cluster is what determines the resilience of the VM's data.

This placement is not random; it is dictated by Storage Policies. These policies are the cornerstone of vSAN's availability model, allowing administrators to define the desired level of resilience for each VM on a granular basis.

The most critical setting in a storage policy is Failures to Tolerate (FTT). This setting defines how many host, site, or fault domain failures an object can withstand before becoming unavailable. For example:

•FTT=1: The VM's data can tolerate the failure of one host.

•FTT=2: The VM's data can tolerate the simultaneous failure of two hosts.

The whitepaper emphasizes an important distinction: the FTT setting applies only to failures for the hosts that the object resides on, not the total number of failures within a cluster. This object-based approach is what allows vSAN to decouple availability considerations from cluster size, making it less susceptible to the impacts of discrete failures as the cluster size increases.

Once the FTT level is set, the policy defines how that resilience is achieved through a data placement scheme. vSAN primarily uses two methods:

1.RAID-1 (Mirroring): This method creates one or more full, synchronous copies (mirrors) of the object's components on different hosts. It offers the best performance but comes at a higher capacity cost (e.g., FTT=1 requires 2x the capacity).

2.RAID-5/6 (Erasure Coding): This is a more space-efficient method that stripes data and parity information across multiple hosts. RAID-5 can tolerate one failure, while RAID-6 can tolerate two. Historically, erasure coding incurred a performance penalty, but the VMware whitepaper highlights that with the vSAN Express Storage Architecture, RAID-5/6 can be used with performance comparable to RAID-1, making it the preferred choice for most workloads.

Thanks to ESA, RAID-1 mirroring should now primarily be reserved for site-level resilience in Stretched Clusters, as noted in the documentation.

The chosen resilience policy has implications for the cluster size. More advanced protection schemes require more hosts to distribute the data and parity components. The whitepaper provides clear guidance on minimum and recommended host counts:

The recommended configuration includes an additional host beyond the minimum, allowing vSAN to automatically repair data and reestablish the prescribed level of resilience in the event of a sustained host failure.

vSAN 8 and later simplify this process with Auto-Policy Management. As described in the whitepaper, this feature allows vSAN to automatically determine the most appropriate and efficient storage policy based on the characteristics of the cluster, ensuring optimal resilience without manual intervention.

One of the most impressive features highlighted in the VMware documentation is the Adaptive RAID-5 Erasure Coding capability in ESA. This feature dynamically adjusts the data structure based on the number of hosts in the cluster. For clusters with fewer than six hosts using FTT=1 with RAID-5, vSAN will stripe the data with parity across three hosts. For clusters with six or more hosts, the same policy rule will stripe the data with parity across five hosts, providing even better distribution and efficiency.

This adaptive approach ensures that vSAN automatically optimizes for the best balance of capacity efficiency and performance as your infrastructure grows.

VMware vSAN provides a robust and highly configurable set of availability technologies designed for the modern, dynamic data center. By abstracting resilience into simple storage policies, it empowers administrators to easily protect their virtual machines against a wide range of hardware failures.

The introduction of the Express Storage Architecture (ESA) marks a pivotal moment for hyper-converged infrastructure. By leveraging a single-tier NVMe architecture and making space-efficient RAID-5/6 erasure coding as performant as traditional mirroring, ESA delivers unprecedented levels of resilience, efficiency, and performance. As organizations continue to scale their virtual environments, vSAN's object-based, policy-driven approach ensures that data availability and protection can scale right along with them.

This article is based on VMware's official whitepaper: "vSAN Availability Technologies: Resilience Capabilities for vSAN in VMware Cloud Foundation 9.0" (December 12, 2025).

📄 Download the full whitepaper: https://www.vmware.com/docs/vmw-vSAN-Availability-Technologies

Great news for all VMware specialists! Broadcom has announced a new exam: Advanced VMware Cloud Foundation 9.0 Storage (3V0-23.25). This exam leads to the coveted VMware Certified Advanced Professional - VMware Cloud Foundation 9.0 Storage (VCAP - Storage) certification.

This exam is designed for experienced VMware professionals who want to validate their expertise in designing, implementing, and managing advanced storage solutions within a VMware Cloud Foundation environment. If you're a system administrator, virtualization engineer, storage professional, or VMware Cloud Foundation architect with at least 12-18 months of hands-on experience with VMware vSAN (including the Express Storage Architecture - ESA), then this exam is for you.

• Exam Name: Advanced VMware Cloud Foundation 9.0 Storage
• Exam Code: 3V0-23.25
• Certification: VMware Certified Advanced Professional - VMware Cloud Foundation 9.0 Storage (VCAP - Storage)
• Number of Questions: 60
• Time Limit: 135 minutes
• Passing Score: 300 (on a scale of 100-500)
• Format: Proctored exam via Pearson VUE, featuring a variety of question types including multiple-choice, build-list, matching, drag-and-drop, point-and-click, and hot-area.

Let's break down the exam sections and what you need to know for each.

This section focuses on the foundational knowledge of storage architectures. You should be able to differentiate between HCI and traditional storage architectures and understand the use cases for different storage types (iSCSI, vSAN, NFS, FC, NVMe).

Study Tips:

• Review the fundamentals of storage protocols and their characteristics.
• Understand the pros and cons of HCI and how it compares to traditional SAN/NAS solutions.
• Familiarize yourself with the different vSAN editions and their features.

This section dives into the specifics of VCF and how storage is integrated. You'll need to know the differences between vSAN OSA and vSAN ESA, the components of the vSAN architecture, and how to identify use cases for advanced vSAN features.

Study Tips:

• Get hands-on experience with vSAN ESA. Understand the new architecture and its benefits.
• Review the vSAN Design and Sizing Guide to understand how to properly size a vSAN cluster.
• Explore the use cases for vSAN features like File Services, iSCSI Target Service, and Data Protection.

This section tests your ability to design a vSAN storage solution based on specific requirements. You'll need to be able to choose the right storage solution for a given scenario and design a vSAN cluster that meets performance and availability requirements.

Study Tips:

• Practice designing vSAN clusters for different workloads and use cases.
• Understand the impact of different vSAN policies on performance and capacity.
• Familiarize yourself with the vSAN Stretched Cluster and 2-Node Cluster architectures.

This is the most hands-on section of the exam. You'll need to know how to deploy and configure a vSAN cluster, including a stretched cluster and a 2-node cluster. You'll also need to be able to configure vSAN policies, encryption, and other advanced features.

Study Tips:

• Build a home lab and practice deploying and configuring vSAN. The VMware HOL (Hands-on Labs) are also a great resource.
• Practice common administrative tasks like adding hosts to a vSAN cluster, replacing failed disks, and updating vSAN.
• Get comfortable with the vSAN management interfaces, including the vSphere Client and the vSAN API.

This section tests your ability to troubleshoot and optimize a vSAN environment. You'll need to be able to monitor vSAN performance, identify and resolve common issues, and optimize vSAN for different workloads.

Study Tips:

• Familiarize yourself with the vSAN health checks and how to interpret them.
• Learn how to use the vSAN performance monitoring tools to identify performance bottlenecks.
• Review the vSAN Troubleshooting Guide for common issues and their resolutions.

• Official Exam Guide: Advanced VMware Cloud Foundation 9.0 Storage Exam Guide
• VMware Cloud Foundation Storage: Advanced Design
• VMware Cloud Foundation Storage: Advanced Configuration
• VMware Cloud Foundation Storage: Advanced Troubleshooting
• VMware HOL (Hands-on Labs)
• VMware vSAN Documentation

• Get hands-on experience: This is the most important tip I can give you. You can't pass this exam by just reading books and watching videos. You need to get your hands dirty and build a vSAN lab.
• Don't neglect the fundamentals: Make sure you have a solid understanding of storage fundamentals before you dive into the advanced topics.
• Time management is key: You have 135 minutes to answer 60 questions, so you need to pace yourself. Don't spend too much time on any one question.
• Read the questions carefully: The questions are very specific, so make sure you read them carefully and understand what is being asked.

I hope this study guide has been helpful. Good luck with your preparations!

VMware by Broadcom has released a new technical document that provides a clear and practical overview of vSAN Encryption Services in VMware Cloud Foundation environments. The paper explains how both Data-at-Rest and Data-in-Transit encryption work within vSAN, and how these mechanisms help secure modern private cloud infrastructures.

The document goes into the architectural differences between the vSAN Original Storage Architecture (OSA) and the vSAN Express Storage Architecture (ESA). It explains where encryption takes place in the I/O path, how DEKs and KEKs are managed, and how the placement of encryption operations impacts performance and efficiency. It also details the integration with external Key Management Servers and the use of the vSphere Native Key Provider, as well as the important role of TPM-backed key persistence on ESXi hosts.

In addition, the paper covers operational topics such as enabling or disabling encryption, rekeying operations, secure device wiping, and the behaviour of hosts during boot-up in encrypted clusters. There is also guidance for situations where vCenter Server must be rebuilt, and how to maintain access to encrypted storage during recovery scenarios.

This document is highly relevant for architects, engineers, and anyone working with VMware Cloud Foundation who needs a deeper understanding of vSAN security mechanisms. It offers both conceptual explanations and practical considerations that can be applied directly in production environments.

You can find the official PDF from VMware by Broadcom here.

Are you ready to elevate your VMware expertise and advance your career? In this in-depth presentation, from the Techcon 2025 in Bunnik, VMware expert Eric Sloof provides a comprehensive overview of the significant transformations in the VMware certification landscape. This session is essential for any IT professional working with VMware technologies, from administrators and engineers to architects and support specialists.

This presentation, lasting over 30 minutes, delves into the latest updates and strategic shifts in VMware's certification paths, focusing on the new role-based model for VMware Cloud Foundation (VCF). Eric Sloof, a distinguished VMware Certified Instructor, breaks down the evolution from product-centric badges to a career framework that validates real-world capabilities.

• The New Role-Based VCF Certifications: Discover the new certification tracks for VCF Architects, Administrators, and Support professionals. Understand how these roles are designed to align with your specific job functions and responsibilities.
• The Return of the VCAPs: Learn about the comeback of the VMware Certified Advanced Professional (VCAP) certifications and how they provide a deeper level of specialization in Design, Deployment, and Troubleshooting.
• The Evolved Path to VCDX: Get a first look at the new, role-based path to achieving the prestigious VMware Certified Design Expert (VCDX) certification, the pinnacle of VMware credentials.
• The Broadcom Knights Program: Uncover the details of the exclusive, invite-only Broadcom Knights program, designed for top-tier experts with proven architectural leadership and real-world performance.
• AI and Exam Preparation: Gain valuable insights into the use of AI tools for exam preparation, including a practical example and a discussion of their limitations and potential pitfalls.

Don't miss this opportunity to get ahead of the curve. Watch the full video to gain a clear understanding of the new VMware certification landscape and learn how to strategically plan your career development. Whether you are just starting with VMware or are a seasoned professional, this presentation offers valuable information to help you unlock your full potential.