A concern associated with virtualization is that performance issues with the host could impact the guest operating systems, which are the operating systems that run on virtual machines within the host. For example, if the host has insufficient memory, CPU, disk space, or network bandwidth, it could affect the performance and availability of the guest operating systems and the applications running on them. The physical footprint of servers could decrease within the data center, processing capacity may be shared across multiple operating systems, and one host may have multiple versions of the same operating system are not concerns associated with virtualization, but rather benefits or features of virtualization that can help reduce costs, improve efficiency, and enhance flexibility. References: CISA Review Manual (Digital Version), Chapter 4:
Information Systems Operations and Business Resilience, Section 4.2: IT Service Delivery and Support

The best method to safeguard data on an organization's laptop computers is full disk encryption. Full disk encryption is a technique that encrypts all the data stored on a hard drive, including the operating system, applications, files, and folders. This means that if the laptop is lost, stolen, or accessed by an unauthorized person, they will not be able to read or modify any data without knowing the encryption key or password. Full disk encryption provides a strong level of protection for data at rest, as it prevents data leakage or exposure in case of physical theft or loss of the device.
References:
* How to Protect the Data on Your Laptop
* 6 Steps to Practice Strong Laptop Security

The best detective control for a job scheduling process involving data transmission is job failure alerts that are automatically generated and routed to support personnel. Job failure alerts are notifications that indicate when a scheduled job or task fails to execute or complete successfully, such as due to errors, interruptions, or delays. Job failure alerts can help detect and correct any issues or anomalies in the job scheduling process involving data transmission by informing and alerting the support personnel who can investigate and resolve the problem. The other options are not as effective as job failure alerts in detecting issues or anomalies in the job scheduling process involving data transmission, as they do not provide timely or specific information or feedback. Metrics denoting the volume of monthly job failures are reported and reviewed by senior management is a reporting technique that can help measure and improve the performance and reliability of the job scheduling process, but it does not provide immediate or detailed information on individual job failures.
Jobs are scheduled to be completed daily and data is transmitted using a Secure File Transfer Protocol (SFTP) is a preventive control that can help ensure the timeliness and security of the job scheduling process involving data transmission, but it does not detect any issues or anomalies that may occur during the process. Jobs are scheduled and a log of this activity is retained for subsequent review is a logging technique that can help record and track the status and results of the job scheduling process involving data transmission, but it does not provide real-time or proactive information on job failures. References: CISA Review Manual (Digital Version), Chapter 3, Section 3.2

The auditor's best recommendation prior to go-live is to conduct a mock conversion test. This is because a mock conversion test can help to verify the accuracy, completeness, and validity of the data conversion process. A mock conversion test can also help to identify and resolve any issues or errors before the actual conversion takes place. A mock conversion test can also provide assurance that the converted data meets the business requirements and expectations. References:
* CISA Review Manual (Digital Version), Chapter 3, Section 3.3.21
* CISA Online Review Course, Domain 2, Module 2, Lesson 22

The best way to determine whether unauthorized changes have been made to production programs is to use source code comparison software to compare the current version of the programs with the previous version or the approved version. This will identify any changes that have been made without proper authorization or documentation. Tracing PCRs to logs or vice versa will only verify that the authorized changes have been recorded, but not detect any unauthorized changes. References: Standards, Guidelines, Tools and Techniques
- ISACA, section "IS Audit and Assurance Tools and Techniques"