Explanation
Disk I/O limits are restrictions or controls that limit the amount of disk input/output operations per second (IOPS) that a VM can perform on a storage device or system. CPU oversubscription is a situation where more CPU resources are allocated to VMs than are physically available on the host or server. Disk I/O limits and CPU oversubscription are most likely to cause VDI performance being very slow at the start of the workday, but fine during the rest of the day, as they can create bottlenecks or contention for disk and CPU resources when multiple users log in or launch their VDI sessions at the same time, resulting in increased latency or reduced throughput for VDI operations. References: CompTIA Cloud+ Certification Exam Objectives, page 9, section 1.4

Explanation
A /28 subnet is a subnet that has a network prefix of 28 bits and a host prefix of 4 bits. A /28 subnet can support up to 16 hosts (14 usable hosts) and has a subnet mask of 255.255.255.240. Using a /28 subnet can meet the minimum IP requirement for deploying a web application in a public cloud with two web servers, two database servers, and a load balancer that is accessible over a single public IP, taking into account the gateway for this subnet and the potential to add two more web servers. Using a /28 subnet can provide enough host addresses for the current and future web servers, database servers, load balancer, and gateway, as well as allow for some growth or redundancy. References: CompTIA Cloud+ Certification Exam Objectives, page 15, section 2.8

Explanation
Vulnerability testing is a type of security testing that identifies and evaluates the weaknesses or flaws in a system or service that could be exploited by attackers. Vulnerability testing can help meet security compliance requirements when deploying a new cloud solution, as it can reveal any potential security risks or gaps in the cloud environment and provide recommendations for remediation or mitigation. Vulnerability testing can also help improve security posture and performance, as it can prevent or reduce the impact of cyberattacks, data breaches, or service disruptions. References: CompTIA Cloud+ Certification Exam Objectives, page 14, section 2.7

Explanation
Storage live migration is the best restoration method to restore a VM from backup without changing the current VM's operating state. Storage live migration is a process of moving or transferring storage resources or data from one location to another without affecting or interrupting the operation or performance of the VMs that use them. Storage live migration can help to restore a VM from backup by copying the backup data to a new storage location and switching the VM's storage configuration to point to the new location, without requiring any downtime or reboot.

Explanation
A virtual graphics processing unit (vGPU) is a type of hardware or software that enables a VM to use the physical GPU resources of the host or server for graphics-intensive tasks. Upgrading the vGPU is most likely to solve the issue of VDI performance being slow since the images were upgraded from Windows 7 to Windows 10, as it can provide more graphics processing power and memory for the VMs. Upgrading the vGPU can also improve the user experience and productivity, as it can enhance the display quality and responsiveness of the VDI environment. References: CompTIA Cloud+ Certification Exam Objectives, page
11, section 1.6