CV0-004 Troubleshooting Practice Test 5 — 15 Questions

Question 1

A cloud administrator is troubleshooting an application that is experiencing intermittent timeouts. The application runs on a cloud VM and connects to a cloud database. The administrator sees no errors in the application logs but notices high network latency during peak hours. Which of the following is the MOST likely cause?

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

Accepted Answer

Insufficient provisioned IOPS on the database. Insufficient provisioned IOPS can cause queue buildup and increased latency during peak loads, leading to intermittent timeouts. Option B is incorrect because schema issues would typically cause query errors or failures, not just latency. Option C is incorrect because a missing route would cause complete connectivity failure, not intermittent timeouts. Option D is incorrect because SSL misconfiguration would cause handshake failures and errors, not just latency.

Answer

Incorrect database schema

Answer

SSL certificate mismatch between app and database

Answer

Missing route table entry for the database subnet

Question 2

During a disaster recovery test, a cloud administrator discovers that the standby database in a different region is not synchronized with the primary. The primary database uses asynchronous replication. What is the MOST likely reason for the sync failure?

Accepted Answer

Network latency causing replication lag. Asynchronous replication does not guarantee immediate synchronization; network latency between regions can cause replication lag, meaning the standby may not have the latest data if the primary fails before sync completes. Option A is incorrect because license expiration would typically prevent the standby from starting or functioning, not cause lag. Option C is incorrect because a firewall blocking port 3306 would completely halt replication, not cause lag. Option D is incorrect because while incorrect configuration could cause sync issues, the question specifies a standby database, and a read replica would not be used as a standby; the most likely reason in a DR test with async replication is network latency.

Answer

License expiration on the standby database

Answer

Firewall rules blocking port 3306 between regions

Answer

Incorrect replication configuration using a read replica instead of a standby

Question 3

A cloud administrator notices that a virtual machine is consuming excessive CPU resources with no apparent workload. Which of the following should the administrator investigate FIRST to determine the cause?

Accepted Answer

A runaway process inside the VM. A runaway process inside the VM is the most likely cause when a VM exhibits high CPU utilization without an apparent workload. This could be due to a background service, malware, or an application stuck in an infinite loop. Option A is incorrect because a misconfigured load balancer would direct traffic to the VM, which would result in network and CPU activity associated with processing that traffic, not idle high CPU. Option B is incorrect; CPU hotplug settings affect the ability to add CPUs but do not themselves cause high CPU usage. Option D is incorrect; memory overcommitment affects memory availability, not CPU utilization.

Answer

A misconfigured load balancer sending traffic to the VM

Answer

CPU hotplug settings on the hypervisor

Answer

Memory overcommitment ratio

Question 4

A cloud engineer is troubleshooting a storage performance issue. The storage is backed by a SAN with a mix of SSD and HDD drives. Which of the following metrics would BEST indicate that the storage subsystem is the bottleneck?

Accepted Answer

High disk queue depth and latency. High disk queue depth and latency directly indicate that I/O requests are waiting, which is a classic sign of a storage bottleneck. Low memory usage (A) does not indicate a storage issue. High network utilization (B) could be caused by storage traffic but does not confirm the storage subsystem is the bottleneck; it could be normal. High CPU utilization (D) points to compute, not storage.

Answer

Low memory usage on the hypervisor

Answer

High network utilization on storage network links

Answer

High CPU utilization on all application servers

Question 5

A company is deploying a critical application in the cloud and needs to ensure that it can automatically recover from an intent—a failure of an entire cloud provider region. Which of the following architectures should be implemented?

Accepted Answer

Active-passive deployment across two regions with DNS-based failover. An active-passive deployment across two regions with DNS-based failover ensures that if one entire region fails, traffic is routed to the passive region, providing disaster recovery at the region level. Option B is wrong because multiple availability zones within a single region cannot survive the failure of the entire region. Option C is wrong because auto-scaling groups in a single region do not protect against region failure. Option D is wrong because active-active across AZs within one region also cannot survive a region-level failure.

Answer

Active-passive deployment across multiple availability zones in the same region

Answer

Single-region deployment with auto-scaling groups

Answer

Active-active deployment across multiple availability zones in the same region

Question 6

A cloud administrator is investigating why a virtual machine is running slowly. The administrator checks the hypervisor performance metrics. Which TWO of the following metrics indicate CPU contention? (Choose TWO.)

Accepted Answer

High CPU ready time. CPU ready time (option A) and co-stop time (option C) are both indicators of CPU contention. Ready time is time a VM is ready to run but waiting for CPU; co-stop time is time a VM is stopped because another vCPU in the same VM is contending. Option E (High CPU usage percentage) is normal utilization, not contention. Option B (High disk queue depth) is storage-related. Option D (High memory ballooning) is memory-related.

Answer

High disk queue depth

Answer

High memory ballooning

Answer

High CPU usage percentage

Question 7

A cloud architect is designing a highly available web application. Which THREE of the following components should be configured in at least two availability zones? (Choose THREE.)

Accepted Answer

Web server instances. To achieve high availability across AZs, the load balancer, application servers, and database should be multi-AZ. Auto-scaling groups can launch instances across AZs, but they are not a component themselves; they are a management service. The DNS service is globally redundant by nature, not usually limited to AZs.

Answer

DNS service (e.g., Route 53)

Answer

Auto-scaling group

Question 8

A cloud administrator is troubleshooting an application that is experiencing intermittent timeouts. The application runs on a cloud VM and connects to a cloud database. The administrator sees no errors in the application logs but notices high network latency during peak hours. Which of the following is the MOST likely cause?

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

Accepted Answer

Network ACLs in VPC B are blocking inbound ICMP. Network ACLs are stateless and must allow both inbound and outbound traffic; if they block inbound ICMP, ping fails, making A correct. Host-based firewall rules within the OS of the target instance can also block ICMP, making C correct. B is wrong because security groups in VPC A control inbound traffic to instances in VPC A, not to instances in VPC B. D is wrong because VPC peering supports ICMP. E is wrong because the administrator verified route tables are correct.

Answer

Security groups in VPC A are blocking inbound ICMP

Answer

VPC peering connection does not support ICMP

Answer

Route tables are misconfigured

Question 9

A cloud administrator is starting the nginx web server on a new cloud VM but it fails. According to the exhibit, what is the most likely cause of the failure?

Accepted Answer

Another service is already listening on port 80. The error 'bind() to 0.0.0.0:80 failed (98: Address already in use)' indicates that port 80 is already occupied by another process. Option A is correct. Option B is wrong because SELinux would give a permission denied error, not address in use. Option C is wrong because the error says address in use, not file not found. Option D is wrong because the error is about binding, not about configuration syntax.

Answer

The VM does not have network connectivity

Answer

SELinux is blocking nginx from binding to the port

Answer

The nginx configuration file has a syntax error

Question 10

A cloud administrator is troubleshooting why a newly launched VM did not complete its initialization. According to the exhibit, what is the most likely cause?

Accepted Answer

The package repository is not configured correctly. The error 'E: Unable to locate package python3-pip' indicates that the package repository is not configured correctly or the package does not exist in the configured sources. This prevents cloud-init from installing the specified package, so the most likely cause is an incorrect repository configuration. Therefore, option B is correct. Option A is incorrect because cloud-init is executing commands, showing it is installed. Option C is incorrect because the error is about a missing package, not a syntax error. Option D is incorrect because the command ran successfully, indicating no network issues; the problem is repository configuration.

Answer

Cloud-init is not installed on the VM

Answer

The cloud-init user data script contains a syntax error

Answer

The VM does not have internet access

Question 11

A cloud administrator is troubleshooting why web-server-01 is not receiving traffic from an internet-facing load balancer. The load balancer is in the same VPC and subnet. According to the exhibit, what is the most likely reason?

Accepted Answer

The security group attached to the instance does not allow traffic from the load balancer. The exhibit likely shows the instance's security group 'web-sg' but no inbound rule allowing HTTP traffic from the load balancer. Since the load balancer is internet-facing and in the same VPC, it can route traffic to the instance via private IP. However, the instance's security group must explicitly allow inbound traffic from the load balancer (or its security group). Without that rule, traffic is blocked. Therefore, the most likely reason is the security group not allowing traffic from the load balancer, making option A correct.

Answer

The instance is in a stopped state

Answer

The instance is not in the same VPC as the load balancer

Answer

The instance does not have a public IP address

Question 12

A cloud user is unable to connect to a web server VM from the internet after a security group rule was modified. The VM is running and can be pinged from other VMs in the same subnet. What is the most likely cause?

Accepted Answer

The inbound rule for HTTP/HTTPS was removed or misconfigured.. Modifying a security group rule likely removed or misconfigured the inbound HTTP/HTTPS rule, blocking internet traffic to the web server. The VM is accessible from other VMs in the same subnet (via private IP), indicating the OS and local services are running, but internet connectivity is controlled by the security group. Option A (local firewall) is unlikely because internal ping works. Option B (missing default gateway) would affect all outbound and inbound traffic. Option D (DNS) affects name resolution, not direct IP connectivity.

Answer

The VM's local firewall is blocking the traffic.

Answer

The VM's routing table is missing a default gateway.

Answer

The VM's DNS settings are incorrect.

Question 13

An administrator notices that a cloud-hosted database is experiencing high latency during peak usage. The CPU and memory utilization on the DB server are below 50%, but disk IOPS are consistently at the provisioned limit. What should the administrator check first?

Accepted Answer

Check if the storage volume has an IOPS cap.. The symptoms (high latency, low CPU/memory utilization, but disk IOPS at provisioned limit) indicate the storage volume's IOPS cap is being hit, causing queueing and latency. Option A is incorrect because network bandwidth is not indicated as the bottleneck; CPU and memory are low, and latency is tied to disk. Option B is incorrect because adding storage volumes would not directly address the IOPS cap; it might spread load but does not increase the per-volume IOPS limit. Option D is incorrect because increasing vCPUs would not resolve an IOPS limitation; the CPU is not saturated.

Answer

Check network bandwidth between the DB and application servers.

Answer

Add additional storage volumes and stripe data.

Answer

Increase the number of vCPUs on the DB server.

Question 14

A hybrid cloud setup uses a site-to-site VPN between on-premises and a public cloud. Users report intermittent connectivity failures. Traceroutes show packets dropping after a specific hop. What is the most likely cause?

Accepted Answer

The MTU setting on the VPN endpoint is too low, causing packet fragmentation.. An MTU mismatch within the VPN tunnel can cause packets to be fragmented or dropped when they exceed the MTU size, leading to intermittent connectivity issues. Traceroute showing drops after a specific hop suggests fragmentation problems. Option A is incorrect: missing routes would cause complete lack of connectivity, not intermittent drops. Option B is incorrect: incorrect pre-shared keys would prevent the VPN tunnel from establishing at all. Option C is incorrect: an overloaded gateway might cause latency or failures but typically not specific hop drops in traceroute.

Answer

The routing tables on the cloud side are missing routes for the on-premises network.

Answer

The VPN tunnel is misconfigured with incorrect pre-shared keys.

Answer

The VPN gateway is overloaded due to too many tunnels.

Question 15

A cloud administrator cannot deploy a new VM from a custom image. The deployment fails with an error stating 'Incompatible hypervisor version'. What is the most likely cause?

Accepted Answer

The image was created on a newer hypervisor than the current host.. If the custom image was created on a newer version of the hypervisor, it may include features or configuration that are not supported by the older hypervisor version on the host, causing the 'Incompatible hypervisor version' error. Option B is incorrect because virtual hardware version typically relates to compatibility within the same hypervisor, but the error is specifically about hypervisor version mismatch. Option C is incorrect because a corrupt image would typically cause different errors (e.g., file read failure). Option D is incorrect because the error is about hypervisor compatibility, not storage backend support.

Answer

The VM's virtual hardware version is too old.

Answer

The image file is corrupt.

Answer

The storage backend does not support the image format.