VMware Updated 5V0-22.23 Exam Questions and Answers by saoirse

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

The two prerequisites for using the TRIM and UNMAP capability of vSAN are:

• B. The vSAN cluster is an all-flash architecture. TRIM and UNMAP are only supported on all-flash vSAN clusters, as they can reclaim space from flash devices that use thin provisioning. TRIM and UNMAP are not supported on hybrid vSAN clusters, as they cannot reclaim space from magnetic disks that use thick provisioning1.
• D. TRIM and UNMAP is enabled. TRIM and UNMAP are disabled by default in vSAN, as they might have a performance impact on some workloads. To enable TRIM and UNMAP on a vSAN cluster, the administrator must use the following RVC command: vsan.unmap_support –enable2. After enabling TRIM and UNMAP, the administrator must power off and then power on all VMs that use the vSAN datastore.

A possible cause of high latency on the vSAN cluster is that there is congestion in one or more disk groups. Congestion is a measure of how busy the storage devices are in handling I/O requests. When congestion is high, it means that the storage devices are overloaded and cannot process the requests fast enough, resulting in increased latency and reduced throughput. Congestion can be caused by various factors, such as insufficient cache capacity, disk failures, network issues, or heavy workload. The other options are not likely to cause high latency on the vSAN cluster. The Virtual Machines can use PVSCSI controllers without affecting latency, as they are optimized for high performance. Erasure Coding is a space efficiency feature that does not impact latency significantly. Jumbo frames are not required for vSAN, and enabling them does not guarantee lower latency. References: vSAN Performance Monitor; [vSAN Congestion Explained]

Deploying the application on a new cluster with vSAN 8.0 ESA using a new hardware design is the correct answer because it will satisfy the customer’s requirement for low latency. vSAN 8.0 ESA is a new architecture that uses a storage pool configuration where all disks are treated as capacity disks and use a new algorithm to distribute data across them. This improves the I/O flow, reduces the write amplification, and eliminates the cache tier bottleneck. Using a new hardware design with all-flash disks or NVMe disks will further enhance the performance and latency of the application, as these disks have faster read and write speeds than hybrid disks. Deploying the new applications on the existing cluster with a RAID-6 VM storage policy and an additionalstripe width of 4, deploying the application on a new cluster with vSAN 8.0 OSA using the existing hybrid configuration, and performing an in-place upgrade from vSAN 7.0 U2 OSA to vSAN 8.0 ESA are not valid or optimal solutions for this scenario. Deploying the new applications on the existing cluster with a RAID-6 VM storage policy and an additional stripe width of 4 will increase the resiliency and availability of the data, but it will also increase the network traffic, disk space consumption, and parity calculation overhead, which will negatively affect the latency and performance of the application. Deploying the application on a new cluster with vSAN 8.0 OSA using the existing hybrid configuration will not improve the latency significantly, as vSAN 8.0 OSA still uses the same disk group configuration as vSAN 7.0 U2 OSA, where one disk is designated as a cache disk and the rest are capacity disks. The cache disk can still become a bottleneck for high-performance applications, especially if it is not an SSD or NVMe disk. Performing an in-place upgrade from vSAN 7.0 U2 OSA to vSAN 8.0 ESA is not possible, as vSAN ESA requires a different hardware design than vSAN OSA. The existing disk groups need to be deleted and all disks need to be erased before switching to vSAN ESA. References:

• [VMware vSAN Specialist v2 Exam Preparation Guide], page 6
• What’s New in VMware vSAN 8.0