VMware 5V0-21.21 Exam Dumps & Practice Test Questions

Question 1:

After a failover event in a stretched vSAN cluster, how is read locality managed at the secondary site?

A. 100% of read operations are handled by local vSAN hosts
B. 50% of read operations come from local vSAN hosts
C. 100% of read operations are served from remote vSAN hosts
D. 50% of read operations are served from remote vSAN hosts

Answer: A

Explanation:

In a stretched vSAN cluster, virtual machines and their storage components are distributed across two geographically separate sites: a preferred (primary) site and a secondary (failover) site. One of the fundamental goals of this architecture is to ensure business continuity and high availability in case the primary site becomes unreachable due to planned maintenance or unexpected failure.

Read locality is a performance optimization mechanism in vSAN that ensures read I/O operations are executed from the site where the VM currently resides. When a failover occurs, and the workload is transferred to the secondary site, vSAN automatically adjusts its behavior to support local read locality. This means that 100% of the read operations are performed by vSAN hosts at the local site, where the VM is now running.

This behavior is critical for maintaining performance. If the VM were to issue read requests that are fulfilled by the remote site, it would introduce significant latency due to inter-site communication over potentially long distances. Therefore, once the secondary site takes over, vSAN accesses the locally stored replica of the data to serve all read requests.

The system achieves this by maintaining fully synchronized copies of each data object across both sites. When a failover happens, vSAN simply starts serving I/O from the local replica at the secondary site, with no need to fetch data from the remote (primary) site.

This architecture not only provides fault tolerance but also enhances performance by reducing the time and bandwidth needed for read operations during a failover scenario. This is why Option A is correct: the system ensures that all read operations (100%) are handled by vSAN hosts on the local site after failover.

Options B, C, and D are incorrect because they suggest that reads are still partially or entirely dependent on the remote site, which contradicts how vSAN’s read locality feature functions in a failover situation.

Question 2:

When using a vSAN stretched cluster with no requirement for site-to-site data mirroring, which vSAN policy value should be configured?

A. SFTT = 0
B. SFTT = 1
C. PFTT = 1
D. PFTT = 0

Answer: D

Explanation:

In VMware vSAN stretched cluster configurations, storage policies play a key role in determining how and where data is stored, replicated, and protected across two or more sites. The policies include specific parameters like Primary Failures To Tolerate (PFTT) and Secondary Failures To Tolerate (SFTT).

PFTT controls how many failures the system can tolerate within a site—specifically, in the preferred site. SFTT does the same but applies to the secondary site. When your design explicitly states that cross-site data mirroring is not required, this means you do not need to maintain a replica of the data at the remote site. Instead, the data should reside only within one site (typically the primary).

To achieve this, PFTT should be set to 0. This tells vSAN that no replication or mirroring of data is necessary across sites. The result is that the data object resides entirely within a single fault domain (the primary site), minimizing overhead and avoiding unnecessary duplication.

Setting PFTT = 1, on the other hand, would trigger vSAN to create an additional copy of the data object at the secondary site. This would violate the goal of no cross-site mirroring, leading to additional network usage and storage consumption, which are precisely what we want to avoid in this scenario.

Similarly, SFTT = 1 pertains to the fault tolerance within the secondary site and would only come into play if workloads were actively running from there. However, it is not relevant when there's no cross-site protection required.

Therefore, selecting PFTT = 0 is the correct approach when data mirroring across sites is not desired. It ensures that the data resides locally on the primary site, optimizing both storage usage and performance while maintaining simplicity in the environment.

Options A, B, and C either misapply the concepts or suggest unnecessary fault tolerance configurations that don't align with the stated requirement of avoiding data replication across sites.

Question 3:

Which VMware solution mandates the use of vSAN to automate infrastructure for both VMware Horizon and VMware Tanzu environments?

A. VMware Cloud Foundation
B. VMware Horizon
C. VMware Tanzu
D. VMware vRealize Automation

Answer: B, C

Explanation:

Among the VMware solutions listed, VMware Cloud Foundation (VCF) is the only one that requires VMware vSAN as an integral component. VMware Cloud Foundation provides a comprehensive platform that integrates compute, storage, network, and management into a unified software-defined data center (SDDC). The solution combines vSphere for virtualization, vSAN for storage, NSX for networking, and vRealize Suite for automation and operations.

The use of vSAN in Cloud Foundation is non-optional—it’s the default and required storage layer across the workload domains created within VCF. This tight integration is necessary because Cloud Foundation is designed to automate lifecycle management, including updates and patches across compute, storage, and network components. Without vSAN, this end-to-end automation would not be possible.

More importantly, VMware Cloud Foundation is designed to support VMware Horizon (for virtual desktops) and VMware Tanzu (for modern containerized applications) in a single, cohesive architecture. For both use cases, vSAN provides scalable, policy-based storage that supports performance requirements and high availability. By using vSAN, VCF eliminates the need for external SAN or NAS hardware and instead provides a hyper-converged infrastructure (HCI) model.

Let’s contrast this with the other options:

• VMware Horizon (Option B) is a VDI platform that can run on a variety of infrastructures, including those without vSAN. While vSAN can enhance Horizon deployments by simplifying management and improving performance, it is not mandatory.

• VMware Tanzu (Option C) is used for Kubernetes-based application development and deployment. It can operate with multiple storage backends and does not inherently require vSAN. While vSAN can simplify persistent storage for containers, Tanzu is flexible in its storage integration.

• VMware vRealize Automation (Option D) is a cloud automation tool that provisions infrastructure and applications across a variety of environments. It is storage-agnostic, meaning it works regardless of whether the underlying storage is vSAN, SAN, NAS, or cloud-based.
  In conclusion, VMware Cloud Foundation is the only solution that requires vSAN by design. It is the foundational platform that supports automated infrastructure provisioning for both Horizon and Tanzu, making Option A the correct answer.

Question 4:

When configuring vSAN file services in a vSAN cluster, which two distributed port group security settings are automatically activated? (Choose two.)

A. Forged Transmits
B. Promiscuous Mode
C. DVFiltering
D. Jumbo Frames
E. MacLearning

Answer: C, D

Explanation:

When enabling vSAN File Services in a VMware vSAN cluster, specific network security policies are automatically configured on the associated distributed port groups. These configurations ensure that the network can handle file services securely and efficiently. Among the options, DVFiltering and Jumbo Frames are the two settings that are automatically enabled during the setup process.

DVFiltering (C) refers to Distributed Virtual Switch (DVS) packet filtering rules that control which traffic types are allowed or blocked. Enabling DVFiltering allows the vSAN File Service to enforce specific traffic policies, such as allowing only authorized communication between the file service agents and client machines. This level of control enhances the security posture of the vSAN File Services setup, ensuring that traffic flows are isolated and compliant with intended configurations.

Jumbo Frames (D) enable Ethernet frames larger than the standard 1500 bytes, typically allowing up to 9000 bytes. Enabling jumbo frames significantly improves network efficiency, especially in data-intensive operations like file sharing over NFS or SMB protocols used in vSAN File Services. By reducing the number of packets needed for large data transfers, jumbo frames help reduce CPU overhead and improve throughput between file servers and clients.

The remaining options are not automatically enabled:

• Forged Transmits (A) controls whether a virtual machine can send frames with a MAC address other than its own. It is not automatically required for vSAN file services and may remain disabled unless specific networking behavior is needed.

• Promiscuous Mode (B) allows a network interface to receive all traffic, not just traffic intended for it. This mode is often used in monitoring and intrusion detection but is not suitable nor necessary for vSAN file services, and it remains disabled to preserve security.

• MacLearning (E) controls the ability of virtual ports to learn MAC addresses dynamically. This setting is typically used in advanced network virtualization scenarios and is not related to the requirements of vSAN File Services.

Therefore, DVFiltering and Jumbo Frames are the two policies that vSAN File Services automatically enable, as they are essential for maintaining both security and performance in file-based storage deployments within vSAN environments.

Question 5:

After rebooting a host in an encrypted vSAN cluster, its disk groups appear in a locked state. What is the appropriate action to restore access?

A. Manually update the Host Encryption Key (HEK) on the impacted host.
B. Reconnect to the Key Management Server (KMS) and re-establish trust.
C. Replace the cache-tier devices in each affected disk group.
D. Execute /etc/init.d/vsanvpd restart to trigger a VASA provider rescan.

Correct Answer: B

Explanation:

In a VMware vSAN cluster that utilizes encryption, maintaining secure and continuous access to encryption keys is critical. When a host is restarted, the vSAN encryption mechanism relies on the system’s ability to reauthenticate with the Key Management Server (KMS) to unlock the disk groups and make them operational. If there is a communication failure or broken trust relationship with the KMS, the disk groups will remain locked, rendering the associated data inaccessible.

The Key Management Server operates based on the Key Management Interoperability Protocol (KMIP). Each host must re-establish communication with the KMS upon reboot to retrieve the Host Encryption Key (HEK). If this link is broken—due to network issues, authentication failure, or certificate problems—the encrypted disk groups stay in a locked state.

The correct procedure in this scenario is to restore communication with the KMS and revalidate the trust relationship. Once trust is re-established, the host can securely fetch the necessary encryption keys, allowing the disk groups to unlock and resume normal operation.

Now let’s evaluate the incorrect options:

• A. Manually replacing the HEK may seem like a direct fix, but it's typically unnecessary and risky unless there's a confirmed compromise or corruption of the key. This is not the first or recommended step when encountering locked disk groups.

• C. Swapping out caching devices might help in hardware failure cases, but it does nothing to resolve encryption issues related to key access. It won’t unlock the disk groups if the underlying problem is with the KMS.

• D. Restarting the vsanvpd service only forces a rescan of the VASA providers, which are responsible for reporting vSAN capabilities to vCenter. This operation is unrelated to encryption key retrieval or KMS trust validation.

In conclusion, the disk groups remain inaccessible because the host can’t access the encryption keys. The right course of action is to reconnect the host with the KMS and re-establish trust, making B the correct answer.

Question 6:

Which boot device option is officially supported for ESXi hosts in a vSAN deployment for this customer?

A. Use a 16GB SLC (Single-Level Cell) SATADOM drive.
B. Use a 4GB USB or SD flash device.
C. Use a 16GB MLC (Multi-Level Cell) SATADOM drive.
D. Use a PMEM (Persistent Memory) device for booting.

Correct Answer: B

Explanation:

When configuring a vSAN-based infrastructure, choosing an appropriate boot device for the ESXi hosts is a foundational requirement. VMware supports several types of boot media, but their suitability depends on the size, endurance, and purpose of the device. In typical enterprise deployments, especially where cost, availability, and compatibility matter, using USB or SD flash storage devices for booting is common and officially supported.

Option B, which recommends using a 4GB USB or SD device, aligns with VMware's guidelines for minimal boot device requirements. These flash devices provide sufficient storage for the ESXi hypervisor and are favored for their cost-effectiveness and ease of implementation. They also meet the vSAN requirement that the boot device must be separate from the capacity or cache tiers used by vSAN to avoid performance conflicts.

Let’s analyze the other options:

• A. A 16GB SLC SATADOM device offers high endurance and performance. While it can be used for booting ESXi, especially in high-write environments, it is not a requirement for standard vSAN deployments. The SLC SATADOM’s endurance is overkill for most boot operations, and this option isn’t as widely adopted unless specific workloads demand it.

• C. The MLC SATADOM variant, although cheaper than SLC, comes with lower endurance. VMware doesn’t officially recommend MLC devices for booting due to reliability concerns over time, particularly in environments with frequent write cycles. This option is less suitable than the more stable and proven USB/SD options.

• D. PMEM devices (Persistent Memory) serve advanced use cases like memory-intensive analytics or in-memory databases. These are not designed or recommended for ESXi booting purposes, especially in vSAN clusters, and they’re not part of standard supported configurations.

In summary, while there are multiple boot device options technically available, VMware clearly supports 4GB USB or SD flash devices as a standard for booting ESXi in vSAN environments. They offer a balance of simplicity, cost, and compatibility—making B the correct and most practical answer.

Question 7:

A company has a vSAN 7 stretched cluster initially designed for 250 workloads, but now it must support 500 workloads. The cluster has been expanded from 8 nodes (4-4-1) to 16 nodes (8-8-1). 

What three actions should the administrator take to ensure scalability while keeping resource use low at the witness site?

A. Add the new vSAN witness appliance to vCenter Server
B. Deploy a new large vSAN witness appliance at the witness site
C. Configure the vSAN stretched cluster to use the new vSAN witness
D. Deploy a new extra large vSAN witness appliance at the witness site
E. Upgrade the vSAN stretched cluster to vSAN 7.0 U1
F. Configure the new vSAN witness as a shared witness appliance

Correct answers: B, C, F

Explanation:

When a vSAN stretched cluster is expanded to support more workloads and nodes, the witness component—responsible for quorum and split-brain prevention—must also scale appropriately. However, the goal is to minimize resources at the witness site.

• B. Deploy a new large vSAN witness appliance: This is necessary because the original witness was sized for a smaller cluster. The “large” size supports more components, aligning with the increase in nodes and workloads.

• C. Configure the vSAN stretched cluster to use the new vSAN witness: Simply deploying the new witness isn't enough—it must be actively configured within the cluster to function as intended.

• F. Configure the new vSAN witness as a shared witness appliance: A shared witness allows multiple stretched clusters to use a single witness appliance, reducing overhead at the witness site. Even if only one cluster is active now, configuring the witness for sharing supports efficient resource use in the future.

• A. Adding the witness to vCenter is a basic setup step but not critical to achieving scaling or resource minimization. It’s assumed as part of deployment and not unique to scaling strategy.

• D. An extra-large witness is unnecessary unless supporting very large or multiple clusters. It wastes resources compared to a large shared witness.

• E. Upgrading to vSAN 7.0 U1 might provide feature improvements but is not directly tied to supporting more workloads or minimizing witness overhead. It’s not mandatory for handling cluster expansion.

Question 8:

What are two possible reasons for high backend IOPS during a vSAN workload performance issue?

A. The cluster DRS threshold has been set to Aggressive
B. There is a vSAN node failure
C. The vSAN Resync throttling is enabled
D. The object repair timer value has been increased
E. The vSAN policy protection level has changed from FTT=0 to FTT=1

Correct answers: B, E

Explanation:

High backend IOPS in a vSAN cluster generally signal resynchronization or object rebuild activity, often triggered by failure events or configuration changes.

• B. vSAN node failure: When a node fails, vSAN begins a resync process to rebuild lost or inaccessible components on other nodes. This leads to intense backend disk activity, causing high IOPS.

• E. FTT change from 0 to 1: Moving from FTT=0 (no redundancy) to FTT=1 (mirrored copies) requires vSAN to duplicate all data, which results in a surge of backend write operations as the redundancy is enforced. This is a well-known cause of backend IOPS spikes.

• A. DRS set to Aggressive: This setting affects CPU/memory resource balancing among VMs, not vSAN’s backend disk activity. It doesn’t contribute to backend IOPS.

• C. Resync throttling enabled: This feature limits the amount of I/O vSAN uses for resynchronization. Enabling it should reduce, not increase, backend IOPS.

• D. Object repair timer increased: Delaying repairs (via increased timer value) postpones the start of resync, so it doesn’t directly cause high IOPS. In fact, it delays such I/O spikes.

Question 9:

What is the most likely reason that performance statistics for workloads and their virtual disks are not visible in the vSphere Client when managing a vSAN cluster?

A. vSAN network diagnostic mode has not been activated
B. Proactive tests have not yet been executed on the vSAN
C. The vSAN performance service is currently disabled
D. vSAN verbose performance mode hasn’t been turned on

Correct Answer: C

Explanation:

When managing a vSAN cluster via the vSphere Client, performance metrics such as IOPS (input/output operations per second), throughput, and latency are crucial for monitoring virtual workloads and disk behavior. If these metrics are not being displayed, the most probable cause is that the vSAN performance service is not enabled. This service is explicitly designed to collect, store, and present performance data for the entire vSAN environment, including workloads and disk-level statistics. Without this service running, performance dashboards and charts remain blank or unavailable within the vSphere interface.

Let’s consider why the other answer choices do not address the core issue:

Option A, which refers to vSAN network diagnostic mode, is typically used for troubleshooting network communication within the vSAN cluster. While it is a helpful feature for diagnosing connectivity issues, it does not influence the ability to collect and display performance statistics.

Option B mentions that proactive tests have not been run. Proactive tests are tools that administrators can use to detect configuration inconsistencies, potential failures, or hardware misalignments before they cause problems. However, they are unrelated to the continuous collection of performance metrics. Whether or not these tests have been run does not affect the visibility of workload performance charts.

Option D suggests that verbose performance mode is not enabled. While this mode can provide more granular and detailed metrics for advanced troubleshooting, it is an optional setting that enhances existing data collection. Even when verbose mode is disabled, basic performance metrics should still be visible if the vSAN performance service is turned on.

Therefore, the absence of visible workload and disk performance charts in the vSphere Client is best explained by Option C — the vSAN performance service is disabled. Enabling it from the vSAN cluster settings restores visibility to the performance monitoring tools in the vSphere interface, allowing administrators to track and analyze virtual disk performance effectively.

Question 10:

While performing maintenance on a vSAN host, an administrator realizes that the system is nearing the end of the default repair delay interval. 

Which two commands can be used to extend this repair delay time? (Select two.)

A. /etc/init.d/vsanmgmtd restart
B. esxcli system settings advanced set -o /VSAN/ClomRepairDelay -i 50
C. esxcli system settings advanced set -o /VSAN/ClomRepairDelay -i 80
D. /etc/init.d/clomd restart
E. /etc/init.d/vsanobserver restart

Correct Answers: B, C

Explanation:

In a vSAN cluster, the repair delay timer is an important mechanism that defines how long the system should wait before automatically initiating repairs for degraded or unavailable components—such as when a disk or host is undergoing maintenance. This delay is crucial to prevent premature or unnecessary rebuilds, which can consume significant resources and affect performance.

To extend the repair delay period, the administrator must adjust the ClomRepairDelay setting using the appropriate ESXCLI command. Both Option B and Option C accomplish this using the following syntax:

esxcli system settings advanced set -o /VSAN/ClomRepairDelay -i [value]

In Option B, the delay is set to 50 minutes, while Option C sets it to 80 minutes. These values directly control how long vSAN will wait before repairing a component after it has been marked as inaccessible. This flexibility is particularly useful during long maintenance windows or staged upgrades, where multiple nodes may be taken offline temporarily.

Let’s evaluate why the other options are incorrect:

Option A, /etc/init.d/vsanmgmtd restart, restarts the vSAN management daemon. While this might be helpful for recovering the management plane in some scenarios, it has no effect on repair timing or the ClomRepairDelay setting.

Option D, /etc/init.d/clomd restart, restarts the Cluster Level Object Manager Daemon (CLOMD), which is involved in managing object state and repair logic. However, restarting the daemon doesn't extend or reset the repair delay; it merely refreshes the service.

Option E, /etc/init.d/vsanobserver restart, is used to restart the vSAN Observer tool, a diagnostic and visualization utility. Like the previous options, this tool doesn’t impact the repair delay.

In conclusion, the only valid methods for extending the vSAN repair delay are Option B and Option C, as they directly modify the system’s advanced settings that govern repair timing. Adjusting these values gives administrators more time to complete maintenance tasks without triggering automatic repair operations.