CV0-004 Troubleshooting Practice Test 5 — 15 Questions

Question 1

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. Option C is correct because asynchronous replication can have lag; if the primary fails before sync, data may be lost. Option A is wrong because DR test is not about licensing. Option B is wrong because replication configurations are typically cross-region. Option D is wrong because a firewall blocking port 3306 would prevent any replication, not just async lag.

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 2

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. Option D is correct because a VM with no workload but high CPU is often due to a runaway process, such as a background service or malware. Option A is wrong because CPU hotplug is not common and would not cause continuous high usage without workload. Option B is wrong because memory overcommitment affects memory, not CPU. Option C is wrong while possibly true, it is less likely than a process running inside the VM.

Answer

A misconfigured load balancer sending traffic to the VM

Answer

CPU hotplug settings on the hypervisor

Answer

Memory overcommitment ratio

Question 3

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. Option A is correct because high queue depth indicates many I/O requests waiting, which is a sign of storage bottleneck. Option B is wrong because high CPU on hosts does not directly implicate storage. Option C is wrong because high network utilization could be from storage traffic, but queue depth is more direct. Option D is wrong because memory usage is not directly related to storage performance.

Answer

Low memory usage on the hypervisor

Answer

High network utilization on storage network links

Answer

High CPU utilization on all application servers

Question 4

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. Option C is correct because an active-passive cross-region deployment with DNS failover provides disaster recovery. Option A is wrong because active-active in one region does not cover region failure. Option B is wrong because multi-AZ within one region does not cover region failure. Option D is wrong because a single region with auto-scaling does not survive region 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 5

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 and co-stop time 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 A (CPU usage percentage) is normal utilization, not contention. Option D (Memory ballooning) is memory-related. Option E (Disk latency) is storage-related.

Answer

High disk queue depth

Answer

High memory ballooning

Answer

High CPU usage percentage

Question 6

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 7

A cloud administrator is troubleshooting a network connectivity issue between two VPCs connected via a VPC peering connection. The administrator has verified that the route tables are correct and that the security groups allow traffic. However, instances in VPC A cannot ping instances in VPC B. Which TWO of the following could be causing the issue? (Choose TWO.)

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 ICMP, ping fails. Firewall rules within the OS can also block ping. Option A is wrong because security groups are stateful and would allow return traffic if outbound is allowed. Option D is wrong because routing is verified. Option E is wrong because VPC peering does not depend on IGW.

Answer

Security groups in VPC A are blocking inbound ICMP

Answer

VPC peering connection does not support ICMP

Answer

Route tables are misconfigured

Question 8

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 9

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 name is incorrect or the repository is not configured. Option C is correct. Option A is wrong because cloud-init is running commands. Option B is wrong because the error is about locating a package, not about a syntax issue in cloud-init. Option D is wrong because there is no indication of network issues; the command ran but couldn't find the package.

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 10

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 instance has no public IP address (not shown) and the security group 'web-sg' may not allow HTTP traffic. However, the exhibit does not show security group rules or public IP. The most likely issue is that the instance is in a private subnet without a route to the internet? But the question says load balancer is internet-facing and in same VPC. The load balancer can route to private instances if security groups allow. However, the exhibit shows no public IP, so the load balancer can still reach it via private IP. Actually, the most common issue is security group rules: the load balancer's security group must allow inbound HTTP, and the instance's security group must allow traffic from the load balancer. Without that, traffic is blocked. Option C is correct. Option A is wrong because the load balancer can route to private IPs. Option B is wrong because the instance is running. Option D is wrong because load balancer does not require a public IP on the instance.

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 11

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.. Option A is correct because the security group rule likely blocks inbound HTTP/HTTPS traffic. Option B is incorrect because DNS resolution affects hostnames, not connectivity. Option C is incorrect because routing between VMs works. Option D is incorrect because a firewall on the OS would affect all traffic, not just internet.

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 12

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.. Option B is correct because saturating IOPS is a common cause of high latency. Option A is incorrect because CPU is not maxed. Option C is incorrect because network latency is not indicated. Option D is incorrect as scaling would increase IOPS but not address the limit.

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 13

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.. Option C is correct because MTU mismatch can cause fragmentation issues leading to drops. Option A is incorrect because the VPN tunnel itself is up. Option B is incorrect as routing appears correct. Option D is incorrect because authentication failures would drop the tunnel, not cause intermittent drops.

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 14

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.. Option D is correct because the image was created on a different hypervisor version. Option A is incorrect because the image file exists. Option B is incorrect as compatibility is about hypervisor, not driver. Option C is incorrect because storage is separate.

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.

Question 15

A cloud load balancer is not distributing traffic evenly to backend servers. All servers pass health checks. Which of the following is the most likely cause?

Accepted Answer

Session persistence is enabled and directing traffic to specific servers.. Option A is correct because session persistence (sticky sessions) can cause uneven distribution. Option B is incorrect because health checks pass. Option C is incorrect as capacity is sufficient. Option D is incorrect because health check interval affects removal, not distribution.

Answer

The health check interval is set too long.

Answer

One of the backend servers has reached its connection limit.

Answer

The health check path is incorrect.