To comply with the user requirements, the best options are to install the OS on a RAID 1 array, configure RAID 5 for the application data, and use SSD hard drives for the data application array. Here is why:
RAID 1 is a mirroring technique that creates an exact copy of data on two disks. This provides redundancy and fault tolerance in case of hard drive failure. RAID 1 also improves read performance since either disk can be read at the same time. Therefore, installing the OS on a RAID 1 array meets the first requirement of separating the OS from the application data and protecting it from hard drive failure.
RAID 5 is a striping technique with parity that distributes data and parity blocks across three or more disks. This provides improved performance and storage efficiency compared to RAID 1, as well as fault tolerance in case of a single disk failure. Therefore, configuring RAID 5 for the application data meets the second and third requirements of providing high IOPS performance and data availability.
SSD hard drives are solid-state drives that use flash memory to store data. They have no moving parts and offer faster read and write speeds, lower latency, and lower power consumption than traditional HDDs. Therefore, using SSD hard drives for the data application array meets the second requirement of providing high IOPS performance.
Reference:
https://phoenixnap.com/kb/raid-levels-and-types
https://en.wikipedia.org/wiki/Standard_RAID_levels

A purple screen with white letters on an ESX server indicates a kernel panic, which is a fatal error that causes the system to crash and stop functioning3. The first troubleshooting step that an administrator should perform is to review the log files, which may contain information about the cause of the error, such as hardware failures, software bugs, or configuration issues4. Checking the power supplies (A) may not be relevant, as the system is still displaying a screen. Reinstalling the ESX server or reseating the processors (D) are drastic measures that may result in data loss or further damage, and should only be attempted after ruling out other possible causes. References: 3 https://kb.vmware.com/s/article/1014508 4
https://www.altaro.com/vmware/vmware-esxi-purple-screen-death/

The backplane is a circuit board that connects multiple hard drives to a RAID controller and provides power and data transfer between them. If the backplane has failed, it may cause all the hard drives to be offline and prevent the server from booting into the OS. The fact that replacing one of the drives with a known-good drive did not work, and that taking a drive out of the server and placing it in a spare server made it functional, suggests that the problem is not with the drives themselves but with the backplane. A corrupt kernel (A) would not affect the status of the hard drives, as it is a software component of the OS. Resource misallocation (B) would not cause all the hard drives to be offline, as it is a configuration issue that affects how resources are assigned to processes or applications. Reseating the drives (D) would not help, as it would not fix a faulty backplane. References:
https://www.dell.com/support/kbdoc/en-us/000130114/how-to-troubleshoot-a-faulty-backplane

Explanation
The step that the server administrator should perform before resolving the issue is to determine the probable causes. This step is part of the troubleshooting process that follows a logical and systematic approach to identify and solve problems with servers and applications. The troubleshooting process consists of several steps, such as:
Identify the problem: Gather information from various sources, such as users, logs, or alerts, to understand the symptoms and scope of the problem.
Establish a theory of probable cause: Analyze the information and formulate one or more possible causes of the problem based on evidence or experience.
Test the theory to determine cause: Perform tests or experiments to verify or eliminate each possible cause until the root cause is found.
Establish a plan of action to resolve the problem and implement the solution: Design and execute a plan to fix the problem using appropriate tools and techniques.
Verify full system functionality and implement preventive measures: Confirm that the problem is resolved and that no other issues arise as a result of the solution. Implement preventive measures to avoid recurrence of the problem or improve performance.
Document findings, actions, and outcomes: Record the details of the problem, its cause, its solution, and its outcome for future reference or knowledge sharing. References: [CompTIA Server+ Certification Exam Objectives], Domain 6.0: Troubleshooting, Objective 6.1: Given a scenario involving server hardware issues (e.g., power supply failure), troubleshoot using appropriate tools.

A Full Backup involves copying all data from a system, regardless of whether the data has changed since the last backup. This process ensures that a complete, standalone copy of all data is available, facilitating straightforward restoration without the need for additional backup sets.
Other Backup Types:
* A. Incremental Backup: This method backs up only the data that has changed since the last backup of any type (full or incremental). While it is storage-efficient and has a faster backup time, restoration requires all incremental backups since the last full backup, making the recovery process more time- consuming.
* B. Differential Backup: This approach backs up all data that has changed since the last full backup. It simplifies the restoration process compared to incremental backups, as only the last full backup and the latest differential backup are needed. However, it consumes more storage space and takes longer to perform as time progresses.
* C. Archive: Archiving involves moving data that is no longer actively used to a separate storage system for long-term retention. It is not a backup type but a data management process aimed at freeing up primary storage space.
* D. Snapshot: A snapshot captures the state of a system at a specific point in time. While it provides a quick way to restore a system to a previous state, it is typically stored on the same system and is not a substitute for a full backup.
In summary, the Full Backup is the only method that captures all data irrespective of changes, ensuring a comprehensive and independent data copy.
References:
* CompTIA Server+ Certification Exam Objectives (SK0-005): Security and Disaster Recovery - Explain the importance of backups and restores