Explanation: If the administrator did not explicitly assign a storage policy when provisioning a new VM on a vSAN datastore, the result is that the VM objects will be protected based on the vSAN Default Storage Policy configurations. The vSAN Default Storage Policy is assigned to all VM objects if no other vSAN policy is assigned when provisioning a VM. The default policy contains vSAN rule sets and a set of basic storage capabilities, such as Failures to tolerate set to 1, Number of disk stripes per object set to 1, and Thin provisioning. The other options are not correct. The VM provisioning will not fail, as vSAN requires that every VM has at least one storage policy. The vSphere Web Client will not choose the last vSAN Storage Policy used, as it will always apply the default policy if no other policy is selected. No data protection will not be applied to the VM objects, as they will have at least one replica based on the default policy. References: About the vSAN Default Storage Policy; Using vSAN Policies

Explanation: To enable vSAN ESA, two requirements that need to be met are: vSAN Standard license or higher, and vSAN ReadyNodes configuration. vSAN Standard license or higher is required to use vSAN ESA, as it is a feature that is only available in vSAN 8.0 or later versions. vSAN ESA is an optional, alternative architecture to vSAN OSA that is designed to process and store data with higher efficiency, scalability, and performance. vSAN ReadyNodes configuration is required to use vSAN ESA, as it is a hardware configuration that is pre-configured, tested, and certified for VMware Hyper-Converged Infrastructure Software. Each vSAN ReadyNode is optimally configured for vSAN ESA with the required amount of CPU, memory, network, and storage NVMe devices. The other options are not correct. vSAN Build Your Own configuration is not supported for vSAN ESA, as it might not meet the hardware requirements or compatibility for vSAN ESA. vSAN Witness Appliance is not required to use vSAN ESA, as it is only needed for stretched cluster or two-node cluster configurations. References: vSAN Express Storage Architecture; vSAN ReadyNode Hardware Guidance

Explanation: To spread the components across storage devices as much as possible, the vSAN administrator can configure disk striping in either OSA or ESA. Disk striping is a policy attribute that defines the number of capacity devices across which each replica of a storage object is striped. A higher number of stripes can result in better performance and availability, but also consumes more storage space. Disk striping can be configured in OSA by using the Number of disk stripes per object policy attribute, or in ESA by using the Striping Width policy attribute12 References: 1: VMware vSAN Specialist v2 Exam Preparation Guide, page 14 2: VMware vSAN Design and Sizing Guide, page 32

Explanation: The correct answer is D, add additional capacity disks to each disk group. This is because adding capacity disks to existing disk groups is the fastest and easiest way to expand the capacity of the vSAN datastore without disrupting any ongoing operations or requiring additional hardware. The administrator can add up to five capacity disks per disk group in vSAN OSA, which means each host can have up to 25 capacity disks in total. The administrator should make sure that the new capacity disks are unformatted and not partitioned, so that vSAN can recognize and claim them. The administrator should also manually rebalance the cluster after adding the capacity disks to distribute the data evenly across the new devices. The other options are incorrect for the following reasons:

A, enable Deduplication and Compression on the cluster level, is incorrect because enabling Deduplication and Compression is not a recommended way to expand the capacity of the vSAN datastore. Deduplication and Compression is a space efficiency feature that reduces the logical space consumption of data by eliminating duplicate blocks and applying compression algorithms. However, enabling Deduplication and Compression requires a full data evacuation and resynchronization, which can be disruptive and time-consuming. Deduplication and Compression also introduces additional CPU and memory overhead, which can affect the performance of the cluster. Deduplication and Compression is only supported on all-flash clusters, not on hybrid clusters.

B, add additional capacity by adding a disk on one host and creating a storage pool, is incorrect because creating a storage pool is not supported in vSAN OSA.
A storage pool is a new configuration introduced in vSAN 8 ESA, where all disks are treated as capacity disks and use a new algorithm to distribute data acrossthem. This configuration is not compatible with vSAN OSA, which uses a disk group configuration where one disk is designated as a cache disk and the rest are capacity disks. To use a storage pool, the administrator would need to migrate to vSAN 8 ESA on a new cluster with new hardware.

C, add additional capacity by adding a vSAN ReadyNode to the cluster, is incorrect because adding a vSAN ReadyNode to the cluster is not the fastest or easiest way to expand the capacity of the vSAN datastore. A vSAN ReadyNode is a preconfigured server that meets the hardware requirements for running vSAN.
Adding a vSAN ReadyNode to the cluster would require additional hardware procurement, installation, and configuration. It would also increase the compute capacity of the cluster, which may not be necessary for the workload. Adding a vSAN ReadyNode would also trigger a resynchronization of data across the cluster, which can affect the performance and availability of the cluster.

References:
VMware vSAN Specialist v2 Exam Preparation Guide, page 10

Explanation: To avoid storage policy non-compliance, the vSAN maintenance mode option that should be used is Full data migration. This option evacuates all data from the host to other hosts in the cluster and maintains the current object compliance state. This means that the VM objects will have access to all their replicas and will be compliant with their assigned storage policies. The other options might result in storage policy non- compliance, as they do not guarantee full data redundancy or policy adherence. Ensure accessibility only migrates the components that are essential for running the VMs, but might not have access to all their replicas. Partial maintenance mode is not a valid option for vSAN clusters. No data migration does not evacuate any data from the host and might result in VM unavailability or data loss. References: Working with Maintenance Mode; Place a Member of vSAN Cluster in Maintenance Mode

Explanation: To view the resynchronizing metrics, the vSAN administrator should open the Backend performance category. This category shows the performance of vSAN data components, such as read/write latency, IOPS, throughput, congestion, and resync traffic. The other categories are not relevant for this task. Disks shows the performance of physical disks in the cluster, Host Network shows the network performance of vSAN hosts, and Resvnc Latency shows the latency of resynchronization operations. References: 1, page 23; 3, section 6.4

Explanation: vSphere High Availability is the correct answer because it meets the requirements of making the virtual machine available quickly after a failure occurs and minimizing administrative effort. vSphere HA monitors the health and availability of the hosts and virtual machines in a cluster and automatically restarts any failed virtual machines on other hosts within minutes. vSphere HA also supports proactive HA, which can migrate virtual machines from hosts that are about to fail or have degraded performance. vSphere HA is easy to configure and manage, as it only requires enabling HA on the cluster level and setting some basic policies and options. Distributed Services Engine,Fault Tolerance, and vSphere Distributed Resource Scheduler are not valid or optimal solutions for this scenario. Distributed Services Engine is a new feature in vSphere 7 that provides network services such as firewalling, load balancing, routing, and NAT for virtual machines and containers. It does not directly affect the availability or recovery of virtual machines after a failure. Fault Tolerance provides continuous availability for virtual machines by creating a secondary copy of the virtual machine that runs in lockstep with the primary copy on another host. If the primary copy fails, the secondary copy takes over without any interruption or data loss. However, Fault Tolerance has some limitations and overheads, such as requiring dedicated network bandwidth, supporting only one vCPU per virtual machine, and consuming twice as much CPU and memory resources as a single virtual machine. Fault Tolerance also requires more administrative effort than vSphere HA, as it needs to be enabled and configured for each individual virtual machine. vSphere Distributed Resource Scheduler is a feature that balances the workload and resources across a cluster by automatically migrating virtual machines based on their demand and priority. It does not directly affect the availability or recovery of virtual machines after a failure, although it can work together with vSphere HA to find optimal hosts for restarting failed virtual machines. References:

[VMware vSAN Specialist v2 Exam Preparation Guide], page 11
vSphere Availability
Distributed Services Engine
vSphere Distributed Resource Scheduler

Explanation: The correct answer is A, the disk group must be deleted on each physical host in the vSAN OSA cluster to use the NVMe device. This is because vSAN OSA uses a disk group configuration where one disk is designated as a cache disk and the rest are capacity disks. To replace the cache disk with a different type or size, the disk group must be deleted first, which will erase all data on the disks and trigger a resynchronization of the affected objects. The administrator should put the host in maintenance mode and choose the option to evacuate all data before deleting the disk group. After replacing the cache disk with the NVMe device, the administrator should recreate the disk group and exit maintenance mode. The other options are incorrect for the following reasons:

B, the disk group does not need to be removed before adding new cache, is incorrect because adding a new cache disk to an existing disk group is not supported in vSAN OSA. The cache disk can only be replaced by deleting and recreating the disk group.

C, the host must be removed from vSAN OSA cluster before changing cache devices, is incorrect because removing the host from the cluster is not necessary and will cause more disruption and data loss than putting the host in maintenance mode. Removing the host will also delete its disk groups and require re-adding them after rejoining the cluster.

D, the cache disk drives must have a larger capacity, is incorrect because there is no requirement for the cache disk to have a larger capacity than the existing one. The cache disk size should be determined by the workload characteristics and performance requirements, not by the expansion process. References: VMware vSAN Specialist v2 Exam Preparation Guide, page 10

Explanation: To satisfy the customer’s needs for high-performance, low-latency applications at edge locations, the best deployment option is to use a new three-node vSAN 8.0 All-Flash Cluster with OSA in each edge location and configure each application VM with a RAID-1 VM storage policy. This option will provide the following benefits:

All-flash clusters offer the highest performance and lowest latency for vSAN, as they use flash devices for both cache and capacity tiers. Flash devices have faster read and write operations than magnetic disks, and they also support advanced features such as deduplication, compression, and encryption.
OSA stands for One Socket Architecture, which means that each host has only one CPU socket with multiple cores. This reduces the licensing cost and complexity of vSphere and vSAN, as well as the power consumption and cooling requirements of the hosts. OSA also improves the performance of vSAN by eliminating the NUMA effect, which is the latency caused by accessing memory or devices across different CPU sockets.
RAID-1 is a mirroring technique that creates two copies of each data component and places them on different hosts. This provides high availability and fault tolerance for the application VMs, as they can survive the failure of one host or disk. RAID-1 also offers better performance than RAID-5 or RAID-6, as it does not incur any parity overhead or additional write operations.
The other options are not optimal for the customer’s needs, as they either sacrifice performance or capacity. Option A uses RAID-5, which is an erasure coding technique that splits each data component into three data segments and one parity segment, and distributes them across four hosts. This reduces the capacity consumption by 25%, but it also increases the write latency and network traffic, as each write operation requires four hosts to participate. Option C uses ESA, which stands for Enterprise Storage Architecture, which means that each host has two CPU sockets with multiple cores. This increases the licensing cost and complexity of vSphere and vSAN, as well as the power consumption and cooling requirements of the hosts. ESA also introduces the NUMA effect, which can degrade the performance of vSAN by adding latency to access memory or devices across different CPU sockets. Option D uses RAID-5 with ESA, which combines the disadvantages of both options A and C.

Explanation: To replace a failed cache drive in a vSAN OSA cluster, the vSAN administrator should remove the existing vSAN disk group and physically replace the device. Then check to verify that the ESXi host automatically detects the new device Afterwards manually recreate the Disk Group. This is because when a cache drive fails, it affects the entire disk group that contains it, and vSAN does not allow removing only the cache drive from a disk group. Therefore, the administrator must remove the whole disk group before replacing the cache drive, and then recreate it with the new cache drive and the existing capacity drives. The other options are not correct. Physically replacing the failed cache drive without removing the disk group first might cause errors or inconsistencies in vSAN configuration. vSAN will not automatically create a new disk group or allocate storage after replacing a cache drive, as these actions require manual intervention from the administrator. Rebalancing the cache layer is not necessary after replacing a cache drive, as vSAN will automatically distribute data across all devices in the disk group. References: Replace a Flash Caching Device on a Host; How to manually remove and recreate a vSAN disk group using esxcli

Explanation: The reason why the vSAN administrator cannot find any vSAN performance statistics on the cluster summary page is that the vSAN performance service is not enabled. The vSAN performance service is a feature that collects and analyzes performance metrics and displays them in graphical charts in vCenter. The vSAN performance service must be turned on manually for each vSAN cluster, as it is not enabled by default. The other options are not correct. The integration of vRealize Operations Manager with the vSAN cluster is not required to view vSAN performance statistics, as they are available in vCenter. The administrator’s permissions on the cluster level do not affect the visibility of vSAN performance statistics, as they are accessible to any user who can view the cluster. vSAN performance statistics are not only available via CLI, as they can also be viewed in vCenter using the vSAN performance service. References: About the vSAN Performance Service; Enable or Disable the Performance Service

Explanation: The correct answer is C, reduced vSphere licensing. This is because using a virtual witness appliance instead of a physical witness host can save on vSphere licensing costs, as the virtual witness appliance does not consume a vSphere license. The virtual witness appliance is a preconfigured virtual machine that runs ESXi and is distributed as an OVA file. It can be deployed on any ESXi host that has network connectivity to both data sites of the stretched cluster. The virtual witness appliance does not run any virtual machines other than itself and only hosts witness components of virtual machine objects.
The other options are incorrect for the following reasons:

A, increased vSAN datastore capacity, is incorrect because using a virtual witness appliance does not affect the vSAN datastore capacity. The witness appliance does not store any customer data, only metadata, such as the size and UUID of vSAN object and components. The witness appliance also does not contribute any storage devices to the vSAN datastore.

B, shared metadata between separate clusters, is incorrect because using a virtual witness appliance does not enable sharing metadata between separate clusters. The witness appliance is dedicated to one stretched cluster and cannot serve as a witness for multiple clusters. The witness appliance maintains consistency between the two data sites of the stretched cluster by hosting witness components that act as tie-breakers in case of a site failure or network partition.

D, additional compute capacity for running VMs, is incorrect because using a virtual witness appliance does not provide additional compute capacity for running VMs. The witness appliance does not run any VMs other than itself and does not participate in any compute operations of the stretched cluster. The witness appliance only hosts witness components that consume minimal CPU and memory resources. References:
VMware vSAN Specialist v2 Exam Preparation Guide, page 11 Deploying a vSAN Witness Appliance