Operating System: Assignment

1. In a multiprogramming and time sharing environment, several users share the system simultaneously. This situation can results in various security problems.
a. What are the two such problems?
Ans:
The two problems in Multiprogramming and time sharing environment are Stealing or copying a user's files; Writing over another program's (belonging to another user or to the OS) area in memory; Using system resources (CPU, disk space) without proper accounting; Causing the printer to mix output by sending data while some other user's file is printing. http://wiki.answers.com/Q/What_are_the_main_two_problems_in_multiprogramming_environment_when_processes_are_run_concurrently_and_share_the_resources b. Can we ensure the same degree of security in a time shared machine as in a dedicated machine? Explain.
Ans:
No, because time-shared machines are far less secure, and are very easy to overload the buffers. Also they are much slower to catch a virus. http://wiki.answers.com/Q/Can_we_ensure_the_same_security_in_a_time-shared_machine_as_in_a_dedicated_machine 2. The issue of resource utilization shows up in differenct forms in different types of operating systems. List what resources must be manged carefully in the following settings:
a. Mainframe or Minicomputer systems
Ans:
Memory, CPU, Storage
b. Workstations connected to servers
Ans:
Storage, Network Bandwidth
c. Handheld computers
Ans:
Memory, CPU, Storage, Power
3. Describe the difference symmetric and asymmetric multiprocessing. What are three advantages and one disadvantages of multiprocessor system?
Ans:
The difference between symmetric and asymmetric multiprocessing is that in Symmetric processing treats all processors as equals; I/O can be processed on any of them, while Asymmetric processing designates one CPU as the master, which is the only one capable of performing I/O; the master distributes computational work among the other CPUs.
Advantagesmultiprocessor system:
 Can save