VCP-DCV vSphere Performance and Scaling Practice Test 2 — 15 Questions

Question 1

Refer to the exhibit. An administrator runs the command on an ESXi host to check HTTPS connections. The host is running vCenter Server and several VMs. What is the most likely cause of the TIME_WAIT connection?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

A client closed the HTTPS connection and the host is in TIME_WAIT state.. The TIME_WAIT state is a normal part of TCP connection termination. When a client closes an HTTPS connection, the ESXi host (as the server) enters TIME_WAIT to ensure any delayed segments are not misinterpreted by a new connection. This state is expected and not indicative of a problem.

Answer

A firewall is blocking return traffic from that client.

Answer

The host's TCP stack is misconfigured for high traffic.

Answer

The host is under memory pressure and dropping connections.

Question 2

A company runs a four-node vSphere 7 cluster with all-flash storage and 25GbE networking. The cluster hosts 50 VMs, including a critical database VM with 16 vCPUs and 64 GB memory. The database VM's performance has degraded over the past week. vCenter reports high CPU ready time (average 15%) for the database VM, while other VMs show less than 2%. CPU utilization on the host is 70%. The database VM is configured with CPU affinity pinned to cores 0-15 on a dual-socket host with 16 cores per socket (32 total). The administrator also notices that the database VM's CPU co-stop counter is high. What should the administrator do to improve performance?

Accepted Answer

Remove the CPU affinity setting for the database VM.. The high CPU ready time (15%) and elevated co-stop counter indicate that the database VM is suffering from contention due to CPU affinity pinning to cores 0-15. On a dual-socket host with 16 cores per socket, pinning to cores 0-15 restricts the VM to a single NUMA node, preventing the scheduler from load-balancing across both sockets. Removing the affinity allows the ESXi scheduler to distribute vCPUs across all 32 cores, reducing co-scheduling overhead and ready time.

Answer

Migrate the database VM to a host with fewer VMs.

Answer

Enable CPU hot-add for the database VM.

Answer

Increase the number of vCPUs for the database VM to 32.

Question 3

Match each vSphere command-line tool to its purpose.

Accepted Answer

esxcli: Command-line utility for managing ESXi host settings and performing diagnostics. Common CLI tools in vSphere include esxcli for host configuration, vmkfstools for storage, vCLI for remote command execution, and PowerCLI for automation. Ensure you match each tool to its primary function.

Answer

esxcli: Used for managing virtual machine snapshots

Answer

vmkfstools: Used for managing ESXi host network settings

Question 4

A vSphere administrator notices that a VM running a critical database is experiencing high latency on its virtual disk. The VM uses a VMDK on a datastore shared by several other VMs. The datastore is backed by an all-flash array. Which action would best reduce latency without increasing storage capacity?

Accepted Answer

Enable Storage I/O Control (SIOC) on the datastore. Storage I/O Control (SIOC) can enforce I/O shares and limits to prioritize latency-sensitive VMs. Increasing shares or limits may not reduce latency if the array is saturated. Moving to another datastore may not be feasible.

Answer

Increase the virtual disk shares for the VM

Answer

Move the VM to another datastore

Answer

Set a higher I/O limit on the VM

Question 5

A vSAN stretched cluster is configured with two witness hosts to allow for site failures. Performance troubleshooting reveals that write latency for synchronous writes is higher than expected for cross-site operations. Which setting should be reviewed as a likely cause?

Accepted Answer

vSAN preferred fault domain configuration. In a vSAN stretched cluster, the preferred fault domain determines which site hosts the majority of object components and handles synchronous writes. If the preferred site is misconfigured or not aligned with the actual site affinity, cross-site write latency increases because writes must traverse the inter-site link. Reviewing the preferred fault domain configuration ensures that writes are directed to the local site when possible, reducing latency.

Answer

vSAN deduplication and compression

Answer

vSAN object repair timer

Answer

vSAN network MTU setting

Question 6

An administrator is planning to scale a vSphere cluster from 8 to 16 hosts. Which consideration is most important for maintaining vSphere HA effectiveness?

Accepted Answer

Increase the number of heartbeat datastores per host. As cluster size increases, the number of heartbeat datastores must be sufficient to ensure isolation detection. Admission control policy and slot size also matter but heartbeat datastores are critical for scaling.

Answer

Assign multiple master hosts to the cluster

Answer

Disable admission control to reduce complexity

Answer

Adjust the slot size for admission control

Question 7

In a vSphere 8 environment with vGPU vMotion enabled, an administrator attempts a vMotion of a VM that has a NVIDIA vGPU profile assigned. The vMotion fails with an error. What is the most likely cause?

Accepted Answer

The VM's virtual hardware version is not supported for vGPU vMotion. vGPU vMotion has specific requirements; the VM must use virtual hardware version 19 or later. If the VM uses an older version, vMotion will fail.

Answer

Insufficient network bandwidth between the hosts

Answer

The destination host has a different GPU model

Answer

The vGPU license is not assigned to the VM

Question 8

Which TWO actions can be taken to reduce CPU ready time for a virtual machine? (Select TWO.)

Accepted Answer

Decrease the number of vCPUs to match the workload. CPU ready time measures how long a vCPU waits in the run queue for a physical core, so reducing the number of vCPUs (option B) directly lowers scheduling contention because fewer vCPUs compete for the same physical cores and the hypervisor can co-schedule them more easily. Increasing the CPU shares for the VM (option D) raises its relative scheduling priority, so when there is contention the VM's vCPUs are granted physical CPU time ahead of lower-share VMs, reducing ready time. Option A (CPU hot-add/hot-plug) only changes whether vCPUs can be added while powered on and has no effect on scheduling contention. Option C (migrating to a host with more physical cores) is not the intended fix because the problem is contention on the current host, and adding cores elsewhere does not reduce ready time unless that host is less contended. Option E (adding more vCPUs) is counterproductive, since more vCPUs increase co-scheduling demands and typically worsen CPU ready time.

Answer

Enable CPU hot-add and hot-plug for the VM

Answer

Migrate the VM to a host with more physical CPU cores

Answer

Add more vCPUs to the VM

Question 9

Which TWO conditions are required for a successful vMotion of a powered-on virtual machine? (Select TWO.)

Accepted Answer

The VM must have its virtual disks on shared storage accessible to both hosts. Shared storage for the VM's disks and compatible CPUs are required. Identical network is not necessary; the VM can be reconnected. Same vCenter is not required for cross vCenter vMotion.

Answer

The source and destination hosts must have identical physical network adapters

Answer

Both hosts must be managed by the same vCenter Server

Answer

The VM must be connected to the same VLAN on both hosts

Question 10

Refer to the exhibit. An administrator sees two DRS recommendations. Which action should the administrator take first to reduce cluster imbalance?

Accepted Answer

Migrate DB01 to host04 first. DRS recommendations are prioritized by the impact of the migration on cluster balance. Migrating DB01 to host04 first is typically recommended because it addresses the most significant imbalance (e.g., DB01 consumes more resources or host04 has the most available capacity), yielding the greatest improvement in balance. DRS evaluates each move's effect on the balance metric and prioritizes the highest-impact move.

Answer

Migrate Web01 to host04 first

Answer

Migrate both VMs simultaneously

Answer

Ignore the recommendations; the cluster is balanced

Question 11

Refer to the exhibit. The administrator is troubleshooting performance for VM 'vm2'. Based on the log, what is the performance issue?

Accepted Answer

The VM is not experiencing significant CPU performance issues. The exhibit (not shown) likely displays CPU performance metrics for vm2 that are within normal ranges, indicating no significant CPU contention. In vSphere, CPU ready time is a key indicator of CPU starvation; if the log shows low CPU ready values (e.g., under 5%), the VM is not experiencing CPU performance issues. Thus, the correct conclusion is that there is no significant CPU problem.

Answer

The host is overloaded with too many VMs

Answer

The VM is experiencing high CPU ready time indicating starvation

Answer

The VM has a memory balloon driver issue

Question 12

An administrator notices that a critical virtual machine is running slowly. The VM has 8 vCPUs and 32GB memory. The host is an ESXi 7.0 server with two Intel Xeon Gold 6248 sockets (20 cores each, hyperthreading enabled). The VM's CPU ready time is consistently above 10%. What is the most likely cause?

Accepted Answer

The host has too many VMs running and CPU oversubscription is too high.. CPU ready time above 10% indicates that the VM is waiting for physical CPU resources, which is typically caused by CPU oversubscription on the host. With many VMs competing for limited physical cores, the VM experiences scheduling delays.

Answer

The VM's vCPUs are pinned to a single NUMA node causing contention.

Answer

The VM is over-provisioned on vCPUs relative to the host's physical cores.

Answer

The VM is using Eager Zero Thick disks causing high I/O latency.

Question 13

A company uses vSphere 7 with Distributed Resource Scheduler (DRS). They want to ensure that VMs are migrated to hosts with more available resources during peak load. Which default DRS setting controls the aggressiveness of initial placement and migration?

Accepted Answer

Migration threshold. The DRS migration threshold (also called the migration aggressiveness slider) is the default setting that determines how aggressively vSphere DRS generates initial placement and migration recommendations based on the imbalance between hosts. It ranges from Conservative (priority 1) to Aggressive (priority 5), with priority 3 as the default. Raising the threshold causes DRS to act on smaller resource imbalances, moving VMs to hosts with more available resources during peak load.

Answer

VM monitoring sensitivity

Answer

EVC mode

Answer

HA admission control

Question 14

A vSphere administrator is troubleshooting a performance issue on a VM that has high average latency on its virtual disks. The VM is stored on a VMFS datastore backed by an all-flash array. The VM has 4 vCPUs and 16GB memory. The administrator runs esxtop and sees %USEDRDY: 0.5, %MLMTD: 10, %SWPWT: 0. What is the most likely cause of the high disk latency?

Accepted Answer

The VM is experiencing memory contention that is manifesting as disk latency. The esxtop metrics show %MLMTD (memory limited) at 10, which indicates the VM is experiencing memory contention. When a VM's memory is overcommitted or constrained, the hypervisor may use ballooning or hypervisor swapping, but here %SWPWT is 0, so it's not swapping. However, memory pressure can cause the guest OS to aggressively use its page file or perform more disk I/O, leading to increased disk latency. The high %MLMTD directly points to memory contention as the root cause, which is manifesting as high disk latency because the guest OS is likely paging to disk due to insufficient physical memory. Thus, the most likely cause is memory contention, not CPU ready or storage queue depth.

Answer

Memory ballooning is causing excessive swapping

Answer

CPU ready time is high

Answer

Storage controller queue depth is full

Question 15

An administrator is monitoring a vSphere cluster with 10 hosts. They notice that vCenter Server is responding slowly when performing operations such as creating VMs or applying host profiles. CPU and memory on the vCenter Server are within normal limits. What is the most likely cause?

Accepted Answer

The vCenter Server database is too large and needs to be trimmed.. When vCenter Server's CPU and memory are normal but operations like VM creation and host profile application are slow, the bottleneck is typically the vCenter database (vPostgres or external Oracle/MSSQL). A bloated database with excessive historical tasks, events, and statistics causes slow queries that manifest as UI and API latency. Trimming old tasks/events and running the vCenter database maintenance (or reducing statistics levels) restores responsiveness.

Answer

The vCenter Server is experiencing time synchronization issues.

Answer

The vCenter Server is running on a VM with insufficient network bandwidth.

Answer

The ESXi hosts are all in maintenance mode.