1. In a multiprogramming and time-sharing environment, several users share the system simultaneously. This situation can result in various security problems. a. What are two such problems? b. Can we ensure the same degree of security in a time-shared machine as in a dedicated machine? Explain your answer.

2. The issue of resource utilization shows up in different forms in different types of operating systems. List what resources must be managed carefully in the following settings: a. Mainframe or minicomputer systems b. Workstations connected to servers c. Mobile computers

3. Under what circumstances would a user be better off using a time-sharing system than a PC or a single-user workstation?

4. Describe the differences between symmetric and asymmetric multiprocessing. What are three advantages and one disadvantage of multiprocessor systems?

5. How do clustered systems differ from multiprocessor systems? What is required for two machines belonging to a cluster to cooperate to provide a highly available service?

6. Consider a computing cluster consisting of two nodes running a database. Describe two ways in which the cluster software can manage access to the data on the disk. Discuss the benefits and disadvantages of each.

7. How are network computers different from traditional personal computers? Describe some usage scenarios in which it is advantageous to use network computers.

8. What is the purpose of interrupts? How does an interrupt differ from a trap? Can traps be generated intentionally by a user program? If so, for what purpose?

9. Direct memory access is used for high-speed I/O devices in order to avoid increasing the CPUs execution load. a. How does the CPU interface with the device to coordinate the transfer? b. How does the CPU know when the memory operations are complete? c. The CPU is allowed to execute other programs while the DMA controller is transferring data. Does this process interfere with the execution of the user programs? If so, describe what forms of interference are caused.

10. Some computer systems do not provide a privileged mode of operation in hardware. Is it possible to construct a secure operating system for these computer systems? Give arguments both that it is and that it is not possible.

11. Many SMP systems have different levels of caches; one level is local to each processing core, and another level is shared among all processing cores. Why are caching systems designed this way?

12. Discuss, with examples, how the problem of maintaining coherency of cached data manifests itself in the following processing environments: a. Single-processor systems b. Multiprocessor systems c. Distributed systems