Explanation
The subnet mask is most likely containing an error that prevents the application server from communicating with the newly installed database server. The subnet mask is a binary number that defines how many bits of an IP address are used for the network portion and how many bits are used for the host portion. The subnet mask determines which devices belong to the same network or subnet and can communicate directly with each other without routing or switching devices. The subnet mask of the database server is 255.255.O.O, which means that all 32 bits of its IP address are used for the network portion and none for the host portion, which is invalid and makes it unreachable by any other device on any network or subnet. The subnet mask of the application server is 255.O.O.O, which means that only 8 bits of its IP address are used for the network portion and 24 bits are used for the host portion, which is also uncommon and makes it incompatible with most networks or subnets. References: [CompTIA Server+ Certification Exam Objectives], Domain 4.0: Networking, Objective
4.1: Given a scenario, configure network settings for servers.

Overprovisioning: Involves allocating more virtual resources (e.g., CPU, RAM, storage) to virtual machines than the total physical resources available on a hypervisor. The idea is for resources to be dynamically shared, assuming not all VMs will demand their maximum allocation simultaneously.
Direct Access: This usually refers to technologies like RDMA (Remote Direct Memory Access) that allow for very low-latency, direct access to the memory of another computer over a network.
Link Aggregation: The practice of combining multiple physical network links to create a single logical link with increased bandwidth.
Component Redundancy: Refers to having multiple hardware components (e.g., power supplies, hard drives) to provide fault tolerance.
Scalability: The ability of a system to adapt and handle increased workloads by adding resources.
Reference:
CompTIA Server+ Objectives (Exam codes SK0-004 or SK0-005): Review the sections on virtualization concepts.
Virtualization Technology Documentation: Refer to documentation for popular hypervisors like VMware vSphere, Microsoft Hyper-V, or open-source solutions.

RAID 6 is a RAID level that uses disk striping with two parity blocks distributed across all member disks. It can tolerate the failure of up to two disks without losing any data. RAID 6 can provide a minimum of 10TB of usable storage space with five 4TB disks, as the formula for calculating the RAID 6 capacity is (n-2) x Smin, where n is the number of disks and Smin is the smallest disk size. In this case, the RAID 6 capacity is (5-2) x
4TB = 12TB.
References:
* CompTIA Server+ Certification Exam Objectives1, page 8
* RAID Levels and Types Explained: Advantages and Disadvantages2
* RAID Levels & Fault Tolerance3

The most likely cause of this issue is that the UEFI boot was interrupted by a missing Linux boot file. UEFI (Unified Extensible Firmware Interface) is a standard that defines the interface and functionality of the firmware that initializes the hardware and software components of a system before loading the operating system. UEFI boot is a process that uses UEFI firmware to load and execute a boot loader, which is a program that loads the operating system kernel and other essential files. A Linux boot file is a file that contains information and instructions for the boot loader, such as the location of the kernel, the root file system, and the boot parameters. If a Linux boot file is missing or corrupted, the boot loader cannot find or load the kernel, and the system stops during the boot process with a blank screen and an f prompt.
References: CompTIA Server+ SK0-005 Certification Study Guide, Chapter 4, Lesson 4.1, Objective 4.1