Paper Details
Module 6, Englander Chapters 17 & 18
For problems 1 and 2, a computer has the following four processes that have arrived in the ready queue in the sequence shown below. NOTE: Time slicing is not used, therefore, there are no mandatory time outs.
• Process 1 has a run time of 25 seconds, a priority of 1, and it will require 10 seconds of I/O after 10 seconds of execution.
• Process 2 has a run time of 20 seconds, a priority of 2, and it will require 10 seconds of I/O after 5 seconds of execution.
• Process 3 has a run time of 25 seconds and a priority of 2.
• Process 4 has a run time of 20 seconds and a priority of 1, and it will require 15 seconds of I/O after 10 seconds of execution.
(HINT for problems 1 and 2: Review Module 6 section 2.1.2 for the definitions of these scheduling algorithms and Self-Assessment problems 1-4.)
1. (2 points)If the Round Robin Scheduling algorithm is used, which process completes second and why? At what time does it complete?
2. (2 points)If the Round Robin with Priority Queues Scheduling algorithm is used, which processcompletes second and why? At what time does it complete?
3. (3 points)Explain the trade-offs between contiguous, noncontiguous linked, and noncontiguous indexed file allocation. In particular, note if each can be efficiently used for sequential and random access methods.
4. (3 points)Using a variable-partitioned multiprogramming memory, which of the four holes shown below will be used to satisfy a 55 KB program requirement under the conditions of:
0-10 KB 10-55 KB 55-140 KB 140-215 KB 215-260 KB 260-330 KB 330-350 KB 350-410 KB 410-470 KB
occupied Hole A occupied Hole B occupied Hole C occupied Hole D occupied
___ First-fit
___ Best-fit
___ Worst-fit
(HINT: See Module 6 section 2.2.3 and Self Assessment problem 6.)
5.You are in charge of security for your company and it has just been ground to a halt by a denial of service attack. Describe and justify the steps you will take to immediately counter the attack, identify system vulnerabilities (internal and external), and prevent future attacks. Do not simply do a web search and copy a list, for example from cert.org.