TOP 25 VMWARE INTERVIEW QUESTIONS AND ANSWERS 2023

As the world continually leans into virtualized environments, VMware has become a cornerstone in the IT infrastructure landscape. With the rising demand for VMware professionals, securing a role often means passing a rigorous interview process. If you're gearing up for a VMware interview in 2023, Bilginç IT Academy has you covered. Dive into our compilation of the Top 25 VMware Interview Questions and Answers for this year, crafted to give you an edge. And if you're looking to delve even deeper, explore the specialized VMware courses we offer. 

Let's set you on a path to VMware mastery!

Basic VMware Interview Questions

These frequently requested VMware interview questions will enable you to successfully respond during your upcoming interview and land your desired position.

1- What is VMware, and why is it important in today's IT landscape?

Answer: VMware is a global leader in cloud infrastructure and digital workspace technology. It provides solutions for virtualization, which allows multiple operating systems to run on a single physical machine. This not only maximizes resource utilization but also reduces the costs associated with physical hardware. In today's IT landscape, with the increasing demand for efficient data centers, disaster recovery, and seamless cloud operations, VMware's solutions offer flexibility, scalability, and cost-effectiveness, making them integral for businesses around the world.

2 - Can you explain the difference between vSphere, ESXi, and vCenter?

Answer: 

vSphere: This is VMware's cloud computing virtualization platform. vSphere is a comprehensive suite that includes both ESXi and vCenter among other components. It's designed to transform data centers into aggregated computing infrastructures that include CPU, storage, and networking resources.

ESXi: This is the virtualization platform, or more specifically, the hypervisor that gets installed on the physical machine. It allows multiple virtual machines (VMs) to run on a single physical machine. ESXi takes the place of the operating system.

vCenter Server: This is the centralized management utility for VMware. It allows for the management of multiple ESXi hosts and VMs from a single console. It provides tools for configuring, monitoring, and administering virtualized resources.

3 - What is a Datastore in VMware?

Answer: A Datastore is a storage location (like an HDD or SSD in traditional computing) where virtual machine files are stored in a VMware environment. It can be local on the ESXi host, or it can be remote storage provided over SAN, NAS, or iSCSI among others. Datastores hide the specifics of each storage device and provide a uniform model for storing VM files. They are essential for VM operations such as creating, starting, and stopping VMs.

4 - What is a VMKernel?

Answer: The VMKernel is a fundamental component of ESXi. It's responsible for core services in VMware infrastructure, including but not limited to, VMotion (for live migration of running VMs), storage I/O, and the management of network connections.

5 - How does VMware VMotion work?

Answer: VMware VMotion allows for the live migration of running virtual machines from one physical server to another with no downtime. It works by sending the active memory and precise execution state of the VM over a high-speed network, allowing the VM to switch from running on the source ESXi host to the destination ESXi host instantly.

6 - What are VMware Snapshots?

Answer: VMware Snapshots are a way to capture the state of a virtual machine, including the VM’s memory, VM settings, and virtual disk state, at a given point in time. It's like a "picture" of the VM's state. Snapshots can be used for backups, testing, and other purposes, allowing administrators to revert back to a previous state if needed.

7 - What is DRS in VMware?

Answer: DRS, or Distributed Resource Scheduler, is a feature of VMware vSphere. It dynamically balances resources across various ESXi hosts under a vCenter server. By constantly monitoring resource utilization, DRS can ensure that VM workloads are evenly distributed and ensure optimum performance.

8 - Explain the difference between "Thick Provision" and "Thin Provision".

Answer:

Thick Provision: When a virtual disk is created with thick provision, all the space allocated to the disk is reserved upfront. This means if you allocate 100GB, all 100GB is set aside immediately, even if the VM is using only a fraction of that space.

Thin Provision: With thin provision, the virtual disk starts small and only grows as data is added. So, if you allocate 100GB but the VM only uses 20GB, only 20GB of physical storage is consumed.

9 - How does VMware Fault Tolerance (FT) benefit a VM?

Answer: VMware Fault Tolerance (FT) provides continuous availability to VMs by creating a live shadow instance of the VM. This is done on another physical ESXi host. If there's a hardware issue causing the primary VM to fail, the shadow VM takes over instantly, ensuring zero downtime and no data loss.

10 - What is VDP?

Answer: VDP stands for VMware Data Protection. It's a backup and recovery solution for VMware virtual environments. VDP uses vSphere APIs for data protection to backup VM data and application data without any interference in VM performance.

11 - What is the purpose of VMware vShield?

Answer: VMware vShield is a suite of security tools designed for vSphere virtual environments. Its primary function is to provide network security and firewall capabilities, protect virtualized applications, and manage and enforce security policies across VMs.

12 - Can you explain what "Resource Pool" is in VMware?

Answer: A Resource Pool is a logical abstraction for flexible management of resources. It aggregates CPU and memory, allowing administrators to delegate resources between different workloads and prioritize resources based on business needs. Resource pools can be hierarchical, with parent-child relationships, ensuring efficient utilization and allocation.

13 - What is the role of the vSphere Client?

Answer: The vSphere Client is the primary interface for administrators to manage ESXi hosts and vCenter Server. It's used for tasks such as creating, configuring, and managing virtual machines, as well as setting up and monitoring the overall virtual infrastructure.

14 - What is the meaning of VVol?

Answer: VVol, or Virtual Volumes, represents a significant shift in how storage resources are handled and consumed within a VMware environment. Instead of seeing storage as a flat datastore or a LUN (Logical Unit Number), VVol introduces a more granular and object-based approach. With VVols, individual virtual machine disks and other operational elements (like snapshots, clones, etc.) are stored as separate objects on the storage system. This allows for more precise and flexible management, as the storage policies can be defined and applied at the VM or even the individual VMDK (Virtual Machine Disk File) level. In essence, VVol simplifies storage operations and offers a more dynamic alignment between the VM and the underlying storage.

VMware Interview Questions for Experienced IT Administrators

If you are an experienced IT Admin preparing for an upcoming interview, these questions will help you a lot:

15 - What is the major advantage of VM running under a type 1 hypervisor than type 2 hypervisor?

The primary advantage of a VM running under a type 1 hypervisor (or "bare metal" hypervisor) like VMware ESXi is performance and efficiency. A type 1 hypervisor runs directly on the host's hardware to control hardware and manage guest operating systems, eliminating any middle layer. This direct interface ensures lower overhead, reduced latency, and a smaller attack surface, leading to better VM performance and enhanced security. On the other hand, a type 2 hypervisor (or "hosted" hypervisor) runs atop an existing operating system, introducing an additional layer and potential inefficiencies. For mission-critical, resource-intensive applications, or large-scale virtualization endeavors, type 1 hypervisors are generally the preferred choice.

16 - How would you handle a situation where a VM is experiencing performance issues, such as high latency or slow response times?

Answer:

First, I'd leverage performance monitoring tools within VMware, such as ESXTOP and vCenter performance charts, to pinpoint the cause. I would check CPU, memory, network, and disk usage metrics. Potential causes might include resource contention, VM configuration issues, or external factors like network bottlenecks or storage latency. Depending on the root cause identified, I'd either adjust the VM's resource allocation, migrate the VM to a less congested host using VMotion, optimize the application running within the VM, or collaborate with network/storage teams to address external issues.

17 - How would you securely isolate network traffic for specific VMs in a vSphere environment?

Answer:

To securely isolate network traffic for specific VMs, I would utilize VMware NSX to create micro-segmentation. NSX allows for the creation of fine-grained security policies at the individual VM interface level. This ensures that even VMs within the same subnet can be isolated from each other. I'd also consider creating separate virtual switches or port groups and using VLANs to further segregate traffic.

18 - Describe your experience with VMware Site Recovery Manager (SRM). How would you use it in a disaster recovery scenario?

Answer:

VMware Site Recovery Manager (SRM) is a disaster recovery orchestration tool I've used in previous roles to ensure high availability and business continuity. In a disaster recovery scenario, SRM allows for the automated failover of VMs from the primary site to a secondary disaster recovery site. The failover process, including the order of VM recovery and network configurations, is predefined in recovery plans. I'd ensure regular testing of these recovery plans without affecting production workloads to guarantee smooth operations in the event of an actual disaster.

19 - How do you handle VM backups in a large vSphere environment, and what strategies do you use to ensure data integrity and availability?

Answer:

For VM backups in a large vSphere environment, I typically utilize solutions like VMware VDP or third-party tools like Veeam. For ensuring data integrity, I schedule regular backup verifications and test restores. Implementing deduplication and compression can optimize backup storage. I also advocate for a 3-2-1 backup strategy: keeping three copies of data, on two types of media, with one copy stored off-site. Additionally, to ensure availability, I consider replication to an off-site location or cloud provider for quick recovery in case of major incidents.

20 - Explain the concept of Storage DRS and how it benefits a VMware environment.

Answer:

Storage DRS (Distributed Resource Scheduler) is a feature in VMware vSphere that balances storage workloads with respect to I/O and space capacity. In a manner similar to how DRS works for compute resources, Storage DRS makes decisions about where a disk should reside within a storage cluster. It can make recommendations or automatically move VM disk files between datastores to balance utilization and maintain optimal performance. The primary benefits include improved storage utilization, reduced storage-related bottlenecks, and automated management, freeing up administrative time and ensuring a smooth end-user experience.

21 - What is the difference between VMware HA and VMware FT?

Answer:

VMware HA (High Availability) and FT (Fault Tolerance) are both essential features in vSphere for ensuring VM uptime, but they serve different purposes:

VMware HA (High Availability): HA monitors VMs and ESXi hosts. If a VM fails or becomes unreachable due to issues like OS failures, application crashes, or host hardware problems, HA can restart that VM on another host within the cluster. While HA minimizes downtime, there is still a brief interruption during the VM restart process.

VMware FT (Fault Tolerance): FT, on the other hand, creates a live shadow instance of a VM on another host. The primary and shadow VMs are kept in lockstep, meaning they execute identical operations. If the primary VM encounters an issue, the shadow VM instantly takes over without any perceptible downtime or data loss. FT ensures continuous availability, while HA provides rapid recovery.

In essence, while both are designed to maximize uptime, FT provides zero downtime and zero data loss, whereas HA ensures rapid recovery from failures.

22 - What is the importance of snapshots in VMware?

Answer:

Snapshots in VMware serve as a critical tool for administrators in various scenarios. They capture the current state and settings of a VM, effectively providing a "point-in-time" image. This has several uses:

• Change Management: Before applying patches, updates, or software installations, snapshots can be taken. If something goes awry, administrators can quickly revert to the previous state.
• Testing: For developers and administrators, snapshots offer a sandbox environment. They can test changes without impacting the live system and simply roll back to the snapshot when done.
• Backup and Recovery: While snapshots aren't a replacement for full backups, they can serve as short-term backup solutions, especially for critical changes or updates.
• Forensics and Troubleshooting: In case of system issues or security incidents, snapshots allow admins to analyze a VM's state at a particular point in time, aiding in diagnostics and investigations.

However, it's essential for administrators to manage and monitor snapshots effectively, as prolonged and excessive snapshot use can lead to reduced performance and storage issues.

23 - Describe the purpose and benefits of VMware NSX.

Answer:

VMware NSX is a software-defined networking (SDN) solution that virtualizes networking and security, decoupling them from the underlying hardware. Its primary purposes and benefits include:

• Micro-segmentation: NSX allows for granular security policies down to the VM interface level. This ensures that even VMs within the same subnet can be isolated from each other, enhancing network security.
• Network Function Virtualization: NSX can create virtual network components like routers, firewalls, switches, and load balancers. This flexibility leads to faster network provisioning and agility.
• Cross-cloud Mobility: NSX provides a consistent networking and security framework across on-premises data centers, cloud environments, and hybrid deployments, enabling seamless workload migration.
• Visibility and Troubleshooting: With its monitoring and analytics capabilities, NSX offers insights into virtual network traffic, helping in quick troubleshooting and optimization.

By decoupling network functions from the hardware, NSX brings in agility, security, and scalability to the data center network, mirroring the benefits VMware brought to server infrastructure with virtualization.

24 - How do you handle storage over-provisioning in a vSphere environment?

Answer:

Storage over-provisioning, while beneficial in optimizing storage usage, can lead to potential pitfalls if not managed correctly. Here's how I handle it:

• Monitoring: Regularly monitor datastore capacity using tools like vCenter alarms and performance graphs. This helps in identifying when datastores are approaching their capacity.
• Thin Provisioning Alerts: Set up alerts to notify when VM disk files (VMDKs) are approaching their logical limits.
• Regularly Consolidate Snapshots: Excessive or old snapshots can consume storage rapidly. They should be consolidated and managed effectively.
• Storage DRS: Utilize Storage DRS to balance storage utilization across datastores, ensuring optimal performance and space usage.
• Educate and Collaborate: Work closely with other teams (like application owners) to understand their storage needs and educate them on the implications of over-provisioning.

By being proactive and leveraging vSphere's in-built tools, one can maximize the benefits of over-provisioning while minimizing its risks.

25 - How do you ensure secure communication between VMs in different networks within vSphere?

Answer:

To ensure secure communication between VMs located on different networks within vSphere:

• Network Segmentation: Utilize VLANs and separate port groups on virtual switches to segregate network traffic based on function or sensitivity.
• VMware NSX: Deploy NSX to implement micro-segmentation, ensuring fine-grained security controls even for VMs within the same network segment.
• Firewalls: Implement distributed firewalls available with NSX to control east-west traffic between VMs. Define and enforce granular policies based on VM attributes or user identity.
• Encryption: Use VM encryption, introduced in vSphere 6.5, to ensure data-at-rest encryption. For data-in-transit encryption, consider solutions like IPsec or SSL VPNs.
• Regular Audits: Periodically review and audit network configurations, firewall rules, and access controls to ensure they align with security best practices and organizational policies.

Combining these measures ensures that even if VMs are on different networks or even different data centers, their communication remains secure and compliant with industry standards.

3 Crucial Tips for Your VMware Interview

Understand the Fundamentals and Beyond:

• Depth Over Breadth: While it's essential to have a broad understanding of VMware products and services, it's equally crucial to have an in-depth knowledge of specific areas, especially those relevant to the job role you're interviewing for. For instance, if the role focuses on VMware NSX, ensure you not only understand its features but also real-world use cases, best practices, and common challenges.
• Stay Updated: VMware, like other tech industries, is continually evolving. Make sure you're up-to-date with the latest VMware releases, features, and best practices. This shows your commitment to staying current in your field.

Relate to Real-world Scenarios:

• Experience Speaks Volumes: Interviewers often appreciate when candidates can relate questions to their own experiences. When asked about a particular challenge or concept, relate it to an actual situation you've encountered, how you approached it, and the results.
• Think Holistically: Often, VMware environments don't operate in isolation. They interact with storage solutions, network infrastructure, and other technologies. Demonstrating an understanding of how VMware integrates with other tech components can be a strong asset.

Communication and Soft Skills:

• Explain Complex Concepts Simply: VMware topics can be intricate. The ability to explain complex ideas in simple, understandable terms is invaluable. This not only showcases your depth of understanding but also demonstrates that you can effectively communicate with team members who might not have your level of expertise.
• Ask Questions: Interviews are a two-way street. Asking thoughtful questions about the company's VMware environment, their challenges, and their future plans can show your genuine interest in the role and provide insights that can help you tailor your responses.

Remember, while technical expertise is essential, interviewers also look for candidates who show initiative, a willingness to learn, and the ability to work well in teams. Tailoring your preparation to combine both technical depth and interpersonal skills will set you on the path to a successful VMware interview.