Explanation
The best course of action to preserve business continuity for a very old PC that is running a critical, proprietary application in MS-DOS is to purchase matching hardware and clone the disk. This way, the technician can create an exact copy of the PC's configuration and data on another PC that has the same specifications and compatibility. This will ensure that the application can run smoothly on the new PC without any installation or configuration issues. Performing scheduled chkdsk tests would not help, as chkdsk is a tool that checks and repairs disk errors, but does not prevent hardware failures or software compatibility issues.
Upgrading the hard disk to SSD would not help either, as SSDs may not be compatible with the old PC or the MS-DOS operating system. Performing quarterly backups would help with data protection, but not with hardware availability or software compatibility. References:
https://www.howtogeek.com/199068/how-to-upgrade-your-existing-hard-drive-in-under-an-hour/
https://www.howtogeek.com/66776/how-to-repair-disk-errors-in-windows-7/

The best course of action to preserve business continuity for a very old PC that is running a critical, proprietary application in MS-DOS is to purchase matching hardware and clone the disk. This way, the technician can create an exact copy of the PC's configuration and data on another PC that has the same specifications and compatibility. This will ensure that the application can run smoothly on the new PC without any installation or configuration issues. Performing scheduled chkdsk tests would not help, as chkdsk is a tool that checks and repairs disk errors, but does not prevent hardware failures or software compatibility issues.
Upgrading the hard disk to SSD would not help either, as SSDs may not be compatible with the old PC or the MS-DOS operating system. Performing quarterly backups would help with data protection, but not with hardware availability or software compatibility. References:
https://www.howtogeek.com/199068/how-to-upgrade-your-existing-hard-drive-in-under-an-hour/
https://www.howtogeek.com/66776/how-to-repair-disk-errors-in-windows-7/

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 5 is a RAID level that provides striping with parity, which means that data is distributed across all disks with one disk storing parity information for error correction. RAID 5 can tolerate one disk failure without losing data. RAID 5 provides the most storage as well as disk redundancy out of the four RAID levels given, since it only uses one disk for parity and the rest for data. For example, if four 200GB drives are used in a RAID 5 array, the total storage capacity would be 600GB (200GB x 3), while in RAID 0 it would be 800GB (200GB x 4), in RAID 1 it would be 200GB (200GB x 1), and in RAID 10 it would be 400GB (200GB x 2).
References: https://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_5