The vSphere Client reports that the state of some components stored on the vSAN datastore are in the reconfiguring state.
Which situation causes components to enter this state?
Correct Answer:C
The reconfiguring state indicates that some components stored on the vSAN datastore are being moved or resized to meet a new storage policy requirement. This state can occur when the applied storage policy is modified, such as changing the number of failures to tolerate, stripe width, or object space reservation. The other situations will not cause components to enter this state. References: [VMware vSAN Specialist v2 EXAM 5V0-22.23], page 31
An administrator has 24 physical servers that need to be configured with vSAN. The administrator needs to ensure that a single rack failure is not going to affect the data availability. The number of racks used should be minimized.
What has to be done and configured to achieve this goal?
Correct Answer:D
To ensure that a single rack failure is not going to affect the data availability, while minimizing the number of racks used, the administrator has to do the following:
✑ Distribute servers across at least three different racks. This is because vSAN supports up to three fault domains per cluster, which can be used to tolerate one or two failures. If only two racks are used, then only one failure can be tolerated4
✑ Configure three fault domains. A fault domain is a logical grouping of hosts that share a common failure point, such as a rack or a power supply. By configuring fault domains, vSAN can place replicas of an object across different fault domains, so that a failure within one fault domain does not result in data loss orunavailability4 References: 4: VMware vSAN Specialist v2 Exam Preparation Guide, page 13
A vSAN administrator is tasked to perform an upgrade of a vSAN cluster, including firmware and drivers for its hardware. The vSAN administrator already created an image using vSphere Lifecycle Manager (vLCM).
Prior to selecting Start Remediation, which step should be taken to upgrade the complete
vSAN cluster as a single task?
Correct Answer:A
To upgrade the complete vSAN cluster as a single task, including firmware and drivers for its hardware, the vSAN administrator should select Remediate All through vLCM to upgrade all hosts in the cluster. This option allows the administrator to apply the image created by vLCM to all hosts in the cluster in a single operation, without having to manually remediate each host individually. The other options are not correct, as they do not perform the upgrade of the vSAN cluster as a single task. Placing all hosts in the vSAN cluster into Maintenance Mode is not necessary, as vLCM will automatically place each host into Maintenance Mode before applying the image. Staging the upgrade of the vSAN cluster through vLCM is only a preparatory step that downloads the image components to each host, but does not apply them. Manually remediating one host at a time in the vSAN cluster is not efficient, as it requires more user intervention and time. References: vSphere Lifecycle Manager (vLCM) on HPE; Lifecycle Management with vLCM in vSAN 7 Update 1
What is the purpose of host rebuild reserve in vSAN?
Correct Answer:B
The host rebuild reserve is a feature that allows vSAN to reserve space in the cluster for vSAN to be able to repair in case of a single host failure. This reservation is set to one host worth of capacity, which means that if one host in the vSAN cluster fails and no longer contributes storage, there is still sufficient capacity remaining in the cluster to rebuild and re-protect all vSAN objects. This feature prevents the creation of new VMs or powering on VMs if such operations consume the reserved space. By default, the host rebuild reserve is disabled, but it can be enabled in the vSAN Services configuration. The other options are not related to the hostrebuild reserve. References: vSAN Capacity Management in v7.0U1; Configure Reserved Capacity
A customer has deployed a new vSAN cluster with the following configuration:
5 x vSAN ReadyNodes
All Flash
12 TB Raw Storage
vSAN 8 is deployed with ESA.
New VMs are configured with a RAID-5 VM policy. Which statement is accurate?
Correct Answer:C
vSAN will use a 4+1 RAID-5 data placement scheme with parity will be used is the correct answer because vSAN 8 ESA uses adaptive RAID-5 erasure coding that depends on the number of hosts in the cluster. If the cluster has 6 or more hosts, vSAN will use a 4+1 RAID-5 scheme, where the data is written as a stripe of 4 data bits and 1 parity bit across 5 hosts. This provides a failure tolerance of 1 (FTT=1) and a space efficiency of 1.25x. If the cluster has less than 6 hosts (3 to 5), vSAN will use a 2+1 RAID-5 scheme, where the data is written as a stripe of 2 data bits and 1 parity bit across 3 hosts. This also provides a failure tolerance of 1 (FTT=1) but a space efficiency of 1.5x. In this case, the cluster has 5 hosts, so vSAN will use the 4+1 RAID-5 scheme.
The other options are incorrect for the following reasons:
✑ A, vSAN will use a 2+1 RAID-5 data placement scheme with parity will be used, is incorrect because vSAN will only use this scheme if the cluster has less than 6 hosts but more than 2 hosts. In this case, the cluster has 5 hosts, so vSAN will use the 4+1 RAID-5 scheme.
✑ B, RAID 5 will provide an FTT=2 level of protection in this case, is incorrect because RAID 5 can only provide an FTT=1 level of protection, regardless of the number of hosts or the data placement scheme. To achieve an FTT=2 level of protection, vSAN would need to use RAID 6 erasure coding, which requires at least 6 hosts in the cluster.
✑ D, vSAN will spread the components across all of the disk groups, is incorrect because vSAN will not necessarily spread the components across all of the disk groups in the cluster. vSAN will only spread the components across as many disk groups as needed to meet the storage policy requirements and to balance the load and capacity. In this case, vSAN will only need to spread the components across 5 disk groups for each stripe of RAID-5 data. References:
✑ VMware vSAN Specialist v2 Exam Preparation Guide, page 11
✑ Adaptive RAID-5 Erasure Coding with the Express Storage Architecture in vSAN 8
An existing vSAN OSA cluster has this specification: Four ESXi hosts with all flash configuration
Each with two disk groups
Each disk group with one cache device and four capacity devices There are five more device slots available per host
The CTO would like to provision new applications, and these will need more capacity and performance.
Which two methods should be used by the vSAN administrator to meet this goal with the least amount of impact? (Choose two.)
Correct Answer:CE
Adding one more disk group per host with the same configuration and adding an ESXi host with identical device configuration are the two methods that the vSAN administrator should use to meet the goal of increasing capacity and performance with the least amount of impact. Adding one more disk group per host will increase the raw storage capacity by 20% and also improve the performance by distributing the I/O load across more cache devices and disk groups. Adding an ESXi host with identical device configuration will increase the raw storage capacity by 25% and also improve the performance by adding more compute and network resources to the cluster. Both methods can be done without disrupting any ongoing operations or requiring any data evacuation or resynchronization. The other options are incorrect for the following reasons:
✑ Replacing all capacity devices with a similar larger device is incorrect because it will not increase the performance and will have a significant impact on the cluster. Replacing the capacity devices requires deleting the disk groups, which will erase all data on them and trigger a resynchronization of the affected objects. This can be disruptive and time-consuming, and also introduce additional network and disk traffic.
✑ Replacing all cache devices with a larger device is incorrect because it will not increase the capacity and will have a significant impact on the cluster. Replacing the cache devices also requires deleting the disk groups, which will have the same drawbacks as replacing the capacity devices. Moreover, increasing the cache size may not improve the performance significantly, as vSAN OSA uses afixed cache ratio of 70% for write buffer and 30% for read cache, regardless of the cache device size.
✑ Adding faster cache devices is incorrect because it will not increase the capacity and will have a significant impact on the cluster. Adding faster cache devices also requires deleting the disk groups, which will have the same drawbacks as replacing the cache devices. Furthermore, adding faster cache devices may not improve the performance significantly, as vSAN OSA uses a fixed cache ratio of 70% for write buffer and 30% for read cache, regardless of the cache device speed. References:
✑ VMware vSAN Specialist v2 Exam Preparation Guide, page 10
✑ Expanding a vSAN Cluster